Purpose: It is known from previous studies that reduced grip strength is associated with tennis elbow; however; assessment of muscular strength over other parts of upper limb, particularly wrist and shoulder, has received a little or no attention in the literature. To address possible other upper extremity muscular strength weakness-imbalances in Tennis Elbow, this study aimed to investigate the strength of various upper limb muscle groups in tennis elbow patients and compare them with those of healthy subjects.

Methods: A total of 32 participants were assigned into two groups of Control (N=16) and Tennis Elbow (N=16). In both groups, upper limb maximal isometric muscular of dominant and non-dominant sides was measured at various joints including metacarpophalan-geal (extension & flexion), wrist extension & flexion), grip, and shoulder (internal and external rotation and abduction) using appropriate either commercial or purpose-built dynamometers. Muscular strength and important strength ratios were analyzed and compared in each group (dominant vs non-dominant) and also between Control and Tennis Elbow group using various statistical methods.

Results: Significant dominance difference was found in all strength measurements for Control group but not for Tennis Elbow group indicating a generalized and widespread upper limb muscular weakness associated with tennis elbow. In addition, significant differences were found not only for various hand strength measurements but also for shoulder strength between Control and Tennis Elbow groups (p < 0.05).

Conclusion: This is the most comprehensive study of upper limb isometric muscular strength assessment in Tennis Elbow during recent years. Distributed upper limb muscle strength weakness exists in Tennis Elbow which needs to be addressed within both preventative and treatment strategies.

Purpose: The aim of this study was to evaluate prospectively the outcome following arthroscopic Bankart repair using two types of suture anchors, absorbable and non-absorbable.

Method: Patients with a diagnosis of recurrent traumatic anterior instability of the shoulder, seen between April 2000 and June 2003, in a single unit were considered for inclusion in the study. Patients were assessed preoperatively and postoperatively using a subjective patient related outcome measurement tool (Oxford instability score), a visual analogue scale for pain and instability (VAS Pain and VAS instability) and a quality of life questionnaire (SF-12). Length of follow up was 1.5 to 5 years, mean 2.6 years. The incidence of recurrent instability and the level of sporting ability were recorded. Patients were randomised to undergo surgical repair with either non-absorbable or absorbable anchors.

Results: 130 patients were included in the study. 6 patients were lost to follow up; therefore 124 patients (95%) completed the study. Both types of anchors were highly effective. There were no differences in the rate of recurrence or any of the scores between the two groups. 4 patients in the non-absorbable group and 3 in the absorbable group experienced further episodes of dislocation after a traumatic event: the rate of redislocation in the whole series was therefore 6%. In addition 4 patients, all of them in the absorbable group (4%,) described ongoing symptoms of instability but no true dislocations. 85% of the patients have returned to their previous level of sporting activity.

Conclusions: There are no differences in the outcome of Arthroscopic Bankart repair using either absorbable or non-absorbable anchors. Both are highly effective, showing a redislocation rate of 5.6%.

Purpose: It is known from the literature that gripping, which is commonly used in various work-related, sport-related, and daily activities, activates both wrist extensors and flexors. Pain aggravation occurs during grip due to over-exertion of the extensor muscle group in lateral epicondylitis and grip strength is reduced. Of grip strength studies, few studies have simultaneously investigated muscular response using electromyography as a method of monitoring muscular fatigue or muscular activity of forearm muscles. The fatigability and activity of wrist antagonistic muscles in patients with lateral epicondylitis has not been previously investigated.

Methods: 16 tennis elbow patients (Tennis Elbow Group) and 16 healthy volunteers (Control Group) were participated in this study. In both groups, local muscular fatigue and muscular activity were measured for 3 forearm muscles contributing to the wrist extension and 2 muscles contributing to the wrist flexion using EMG and during gripping at 50% maximum voluntary contraction (MVC). Fatigability and activity of muscles then were compared between control and tennis elbow groups.

Results: Grip strength was significantly lower in tennis elbow group than that in control group (p < 0.05). Median frequency (MDF) and root mean square (RMS) of electromyographic signals were used as parameters to measure muscular fatigue and muscular activity, respectively. Further analysis showed no significant difference in the fatigability of forearm muscles between two groups. The activity of Extensor Carpi Radialis (ECR) showed statistically significant reduction in tennis elbow group compared to the control group (p < 0.05).

Conclusion: This is the first study to simultaneously investigate the fatigability and activity of the forearm antagonistic muscle groups in patients with lateral epi-condylitis. The fact that ECR showed similar level of muscular fatigue to other muscles despite decreased muscular activity may indicate of higher fatigability of this muscle in tennis elbow. Furethermore, decreased muscular activity of ECR may be a part of mechanism to protect the muscle from further injury in tennis elbow patients.

A prospective study was carried out over a period of 4 years. 31 patients with a mean age of 49 years were treated using the clavicular hook plate. The mean follow up was 28.34 months. 23 patients were operated primarily and 8 patients were operated for symptomatic non-union.

All the patients achieved clinical and radiological union in a mean 12.71 weeks. According to Constant scoring the mean was 94. According to HSS (Hospital for Special Surgery) scoring 9 patients had excellent, 21 had good.

The clinical results of the clavicular hook plate were good leading to good shoulder girdle function.

Scapular instability is a disabling deformity that results in pain and influences the overall upper limb function ; for which scapular stabilization may be necessary.

Aim: To review the results of this procedure.

Methods: 9 patients who underwent this procedure could be contacted and were assessed. We used the Disability of Arm, shoulder and Hand score(DASH) and the constant score for shoulder function including subjective assessment of patients pain and overall satisfaction and radiographs for evidence of unionwith a mean age of 36 yrs(range 21–57 yrs), performed in the period between July 1996 and October 2002 with a mean follow up period of 35.7 months,(range 10–72 months).6 of them were primary procedures and two were revisions for failed primary stabilisation . The main pre-operative complaint of these patients was dragging pain, scapular winging, painful forward flexion and abduction and sense of instability. The underlying pathology was Fascio-scapulo-humeral dystrophy in 3, sprengels shoulder in 2,brachial plexus palsy in 1, following trapezius muscle excision in 1, residual winging following shoulder fusion in 1.

The technique used for fusion was plate and wires in 6, Rush pin and wires in 2. All of them had bone grafting .

At the last follow up the mean DASH score was 37 and the mean constant score was 74.67.

All patients had mild or no pain,felt their scapula stable and were satisfied with the outcome. The main post operative complaint was wire breakage and migration that necessitated removal in 3 patients.

We conclude that scapulothoracic fusion is a valuable procedure and can restore reasonable shoulder function and relieve pain in patients with scapular instability.

Introduction and Aims: To determine differences in rotator cuff tissue with duration of symptoms and tear size

Method: Rotator cuff tissue was obtained at debridement from 44 patients undergoing surgical repair. Pathological assessment was performed on H& E sections. Features evaluated included inflammation, micro-calcification, tendolipomatosis and fibroblast hypocellularity. Matrix quality and endothelial cell proliferation were examined. Patient details – age, tear size and duration of symptoms were extracted from notes.

Results: Matrix quality was significantly worse in small tears (p=0.028), particularly the extent of mucoid degeneration in the debrided tissue (p=0.017). Presence of a healthy cut margin was more likely in a large tear (10/14). Poor matrix was significantly associated with symptom duration > 15months (p=0.006) especially microcalicification (p=0.019) and mucoid degeneration (p=0.047). Endothelial cell proliferation was significantly more apparent in patients with longer duration of symptoms: previous vascular tufting (p=0.001) and ongoing vascular proliferation (p=0.019). Of 27 patients > 15months symptoms, vascular proliferation was strongly correlated with split collagen fibres (p< 0.018) and mucoid degeneration (p< 0.018) but not microcalcification. Tendolipomatosis was strongly correlated with ongoing vascular proliferation (p< 0.0006).

Conclusion: Successful surgical repair is only achieved in 30% patients with rotator cuff tears. Improvements in this success rate will be essential in order to maintain the independent lifestyle of an elderly population. Although the tissue examined here is debrided, and hence worst case tissue, several time-dependent processes are ongoing, degeneration, repair and remodelling. Matrix quality is deteriorating, however, this maybe supportive of the angiogenic component of repair. Remodelling may be seen in the increased probability of a healthy cut margin from patients with longer symptom duration.

Introduction and Aims: To determine whether non-steroidal anti-inflammatory drugs (NSAID) administration influences ongoing endothelial cell proliferation in tom rotator cuff?

Method: Rotator cuff tissue, obtained at debridement from 53 patients undergoing surgical repair, was fixed and embedded. Pathological assessment was performed on H& E sections. Ongoing vascular proliferation was identified by plump endothelial cells and budding of vessels. Patient cuff details and pre-operative drug prescription data was obtained from patients’ notes and by telephone from general practitioners. The drugs used were NSAIDs (including Aspirin, Ibuprofen and Diclofenac), COX 2 inhibitors and Opiates. The data was analysed using the SPSS program and the Pearson Chi-square test.

Results: Of the 35 patients taking analgesics, vascular proliferation was absent or reduced in 22 (63%). Twenty of these patients were taking NSAIDs. Four patients were taking only COX-2 inhibitor drugs; all these patients had increased vascularity. Twenty-three patients were taking codeine-based analgesics. Of 10 patients using codeine without NSAIDs, eight demonstrated active ongoing vascular proliferation (p=0.027).

Conclusion: Patients taking NSAIDs showed a significant reduction in ongoing vascular proliferation. If endothelial cell proliferation is an important component of repair in either the onset or post-operative stages of rotator cuff pathology, then attempts at repair could be compromised by inadequate local function of the vascular system. We have previously identified strong p27 positivity in rotator cuff endothelial 0 cells. NSAIDs can impair healing by inhibiting angiogenesis; the mechanism includes upregulation of p27 in endothelial cells. More work should be done to clarify this matter in the rotator cuff.

Little is known about how arthroscopic knots behave in terms of reverse slippage and creep during the first few hours following a Bankart repair. We aimed to assess differences between knot types tied with a variety of suture materials when exposed to loading which might be expected during the first 12 hours following a repair.

This study uses an apparatus to model the tensioning of a slipknot, the closing of a Bankart lesion and any reverse slippage occurring on removal of the tensioning force. Eight examples each of the Duncan loop and SMC knots were tied by an experienced surgeon using 4 different suture materials (PDS, Ethibond, Panacryl, Fibrewire). An arthroscopic knotting technique was used utilising a knot pusher. Each knot was locked with 3 half-hitches alternating direction and post each time. Any reverse slippage occurring during the tying process was recorded. Each knot was then left in situ for 12 hours under loads equivalent to a repaired Bankart lesion and any subsequent reverse slippage was recorded at the end of this period.

After initial passing of the Duncan loop the sutures were ranked inversely to size of suture loop (resistance to slippage) in order Panacryl (5.08±0.15mm); Fibrewire (5.7±1.03mm); Ethibond (7.22±3.47mm) and PDS (8.2±5.16mm). After passing of locking hitches, they ranked Ethibond (5.13±0.24mm); PDS (5.15±0.09mm); Panacryl (5.17±0.13mm) and Fibrewire (5.66±0.5mm – significant p< 0.05). After 12 hrs, some evidence of reverse slippage was noted, Ethibond (5.23±0.27mm); PDS (5.27±0.13mm); Panacryl (5.3±0.16mm) and Fibrewire (5.66±0.5mm – significant p< 0.05). The SMC knot showed similar results.

If a slip-knot back slips it can be tightened with the first locking hitch. After this further hitches do not tighten the knot further. Some slippage was noted during the first 12 hrs. Using arthroscopic techniques, Fibrewire performs less well than other materials.

Introduction Chronic venous insufficiency can be a disabling complication following otherwise successful arthroplasty. The objectives of this study were 1) To evaluate correlation between the CIVIQ (questionnaire) score and the clinical score in a cohort of patients with lower limb arthroplasty. 2) To evaluate if CIVIQ score can predict post-phlebitic syndrome.

Methods A cohort of 44 patients at least three years following primary lower limb arthroplasty was selected. The control group included 22 patients who did not have DVT. The study group included 22 age matched patients who had DVT following the index procedure. CIVIQ score and clinical score was obtained. Statistical analysis included correlations, linear regression analysis and independent sample t-test.

Results The CIVIQ and clinical scores showed significant correlations, with r=0.66 (p 0.01). The linear regression yielded the formula; CIVIQ score equals 32 plus 1.7 (clinical score) with power of 0.9. There was statistically significant difference in the CIVIQ score in the study and control groups (p 0.013, power 0.9).

Conclusions CIVIQ is an effective tool to predict post-phlebitic syndrome in patients with arthroplasty. This is especially useful as it is self administered and hence can be done as a postal or telephone survey.

Introduction: The rotator cuff is subject to constant pressure from the head of the humerus. This tends to ‘wring out’ the blood supply resulting in a functionally avascular critical zone, although microvessels can be identified. This zone is the site of degeneration and tears. Damage repair under these conditions would be difficult. Myofibroblasts are characteristic of the contractile phase of wound healing. We have examined their distribution in both healthy resected and torn, degenerating rotator cuff tissue and correlated their presence with vascularity and hypoxia in the surrounding tissue. Methods: Rotator cuff tissue was obtained from ten patients undergoing surgical repair. The size of tear was 1–4.5cm, Immunohistochemical staining with commercial monoclonal antibodies to HIF-1α (Hypoxia inducible factor), vimentin, smooth muscle actin (SMA), CD31 and VEGF was performed on formalin fixed paraffin embedded tissues. Visualisation used standard DAB chromagen technique. Results: Focal myofibroblast positivity (SMA+/VIM+) was detected, areas of positivity were found at the interface between torn and degenerating tissues adjacent to the tear. Myofibroblasts were absent in degenerating tissue. The areas of myofibroblast positivity were well vascularized, with strong VEGF positivity. Nuclear HIF-1α positivity was identified in the adjacent endothelial cell population and sporadically in fibroblast population, although not in the myofibroblasts. Conclusion: Evidence of an ongoing wound healing response was found in tissue from torn rotator cuffs. However, it was patchy and infrequent.

Background: Microvessels have been identified in the functionally avascular critical zone of the rotator cuff. Inadequate local sprouting of these capillaries might impair attempts at repair. We have identified widespread VEGF positivity in endothelial cells. However, this was accompanied by strong positivity for the cell cycle inhibitor p27 and little proliferation (Ki-67 positivity). Non-steroidal anti-inflammatory drugs (NSAID) can impair healing by inhibiting angiogenesis. The mechanisms include upregulation of p27 in endothelial cells. Objective: Does NSAIDs influence endothelial cell proliferation in torn rotator cuff? Methods: Pathological assessment of Rotator cuff tissue, obtained from 35 patients undergoing surgical repair, was performed on H& E sections. Ongoing vascular proliferation was identified by plump endothelial cells and budding of vessels. Preoperative drug prescription data was obtained from patient’s General practitioners. The drugs used were NSAIDs (including Ibuprofen and Diclofenac), COX2 inhibitors & Opiates. Results: Ongoing vascular proliferation was not identified in 20/35 patients. 25 patients were taking analgesics; vascular proliferation was absent in 15. 20 patients were taking NSAIDs of these 15 demonstrated no ongoing vascular proliferation, (p≤0.014). No significant effect of opiates or COX2inhibitors was found. Discussion: Patients taking NSAIDs showed a significant reduction in vascular proliferation. If endothelial cell proliferation is an important component of repair in rotator cuff tears, more work should be done to clarify this matter.

Tennis elbow (lateral epicondylitis) is a common upper limb condition, possibly resulting from angiofibroblastic degeneration. Conservative treatment comprises corticosteroid injections, rest and splints, however, occasionally surgery is necessary.

Recent data comparing Botulinum Toxin Type A (BTX-A) (Botox®, Allergan Inc, Irvine, CA) with surgery suggested BTX-A is effective in treating resistant tennis elbow by providing temporary, reversible paralysis of affected muscle, thereby alleviating tensile forces and allowing tissue healing.

This double-blind, randomised, controlled trial compared BTX-A with placebo in 40 patients with chronic tennis elbow (> 6 months). Recruited patients were randomised to 50U BTX-A+2mL normal saline or 2mL normal saline (placebo). Injections were administered 5cm distal to the maximal area of lateral epicondyle tenderness. Quality of life (SF-12), pain (visual analogue scale) and grip strength (Jamar dynamometer) were assessed pre- and 3 months post-injection in both affected and non-affected arms. Following BTX-A treatment patients had average 19% improvement in grip strength in the affected arm compared to average 2% for placebo, however, this difference did not reach statistical significance (p=0.08, 95% CI −2.31, 35.64). No difference between the groups was seen for the unaffected arm (BTX-A 4% improvement, placebo 1% improvement).

Both groups showed similar improvements in pain assessment and also in quality of life.

BTX-A treated-patients demonstrated improved grip strength in the affected arm compared to placebo, however this difference was not statistically significant.

The purpose of this study was to analyse the effects of two different biomechanical configurations on the tensile properties of equine patellar tendons. The study looked at a comparison of straight untwisted patellar tendons and double stranded, twisted specimens. The aim was to attempt a more anatomical Anterior Cruciate Ligament configuration when performing reconstruction using the patellar tendon.

Thirty four specimens were harvested and each sample group consisted of a pair of equine ligaments taken from the same animal. The first of the pair served as an ‘untwisted, straight ligament’ control group and the second as the ‘twisted, double stranded test group’. The ligament dimensions were measured for each specimen and the specimen was mounted on an Instron Series 4411© tensile testing machine and tensile load was applied until failure.

Results showed a clearly statistically significant reduction in the tensile properties (p< 0.005) of the twisted double stranded specimens which was against our original hypothesis. The results indicated that the twisted double stranded ligaments had only 65% of the tensile strength of their untwisted counterparts. Similar reductions were demonstrated when calculating energy to yield point and load at zero point yield stress. The results also demonstrated a significant reduction in the stiffness (Young’s Modulus) between the two test configurations.

The application of a double stranded twist to the patellar tendon confers no advantage in terms of tensile property of the ligament. In fact the application of such a model may cause significant reduction in strength and stiffness of the construct which may lead to early failure of the ACL patellar tendon autograft.

Introduction: Distal humeral fractures represent a constant challenge to the most experienced surgeon. This is the first report of the use of an unlinked prosthesis for the treatment of distal humeral fractures in elderly persons.

Materials and Methods: From July 2000 to June 2001, 9 iBP elbow arthroplasties were performed in patients with acute fractures of the distal humerus. The average age of the group was 71 years. The mean interval between injury and TER was 11 days. The follow-up period averaged 12 months (range 5 to 16).

Results: Functional outcome was evaluated with patient-completed questionnaires. All patients had a flexion contracture of the elbow ranging from 15 to 30 degrees. All patients were able to perform daily activities, pain relief was satisfactory and patient satisfaction was high. All elbows met the criteria for functional motion and were stable at the latest follow-up examination. There were no major complications such as dislocation, ulnar nerve dysfunction or deep infection.

Conclusion: Unlinked non-congruous elbow arthroplasty when combined with a surgical exposure that allows proper soft tissue balance and instrumentation that enables correct positioning of the components can be a successful alternative in the management of acute distal humeral fractures in selected patients when conventional fixation is not a viable option.

The use of crude mortality and morbidity data to assess the outcome from surgical intervention can be both dangerous and misleading. Furthermore, differences in outcome when comparing differing units or surgeons may be explained merely by variations in case mix and the type of surgery.

In recent years there have been a number of attempts to devise a reliable method for assessing the outcome from surgical intervention. In the general surgical setting, the POSSUM system has proved to be the most reliable and accurate of all scoring systems so far devised. It is widely applicable in other specialities as it allows comparison based on the patient’s physiological status and the magnitude of surgery. It could be used in any hospital, in elective and emergency operations. The present study attempted to validate the application of this new method of assessing the outcome after orthopaedic surgery.

All consecutive patients admitted to the orthopaedic wards in a district general hospital during a 12 month period in which orthopaedic surgery was performed on a non-day case basis were assessed using the new orthopaedic POSSUM system. POSSUM is an acronym for Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity. POSSUM is a two-part system that scores both physiological and operative factors. It is developed of multivariate discriminate and logistic regression analysis of 62 variables reduced to: * 12 factors, 4 grade physiological score and * 6 factors, 4 grade operative severity score. When these are combined, a numerical estimate of both mortality and morbidity is obtained. Mortality prediction for individual patients was estimated using this equation: Log [risk − (1 − risk)] =−7.04 + (0.13 physiological score) + (0.16 operative severity score)

During the 12 month period, 2326 patients underwent orthopaedic surgery. 44% were in elective setting, 56% were in emergencies. Using the POSSUM logistic regression equations yielded an overall predicted mortality of 53 patients (versus 51 observed) and a predicted morbidity of 254 patients (versus 252 observed).

The present study indicates that orthopaedic POSSUM is accurate in assessing outcome after an orthopaedic operation and can be used as an audit aid to assess the quality of surgical care.

Recently concerns have been raised as to the effect of intra-articular radio-frequency energy on axillary nerve function. In our unit 120 shrinkage procedures have been performed with 5 intra-operative contractions of deltoid and no axillary nerve palsy. In this study we aimed to identify and quantify any changes in axillary nerve function following capsular shrinkage. Needle electrodes were inserted into the deltoid muscle of 10 patients undergoing radio-frequency capsular shrinkage and 3 patients having diagnostic arthroscopy. Recordings of Compound Muscle Action Potentials (CMAPs) were made following pre-operative magnetic coil stimulation of the axillary nerve. The nerve was then monitored during operation. At the end of the procedure, a further recording of CMAP following axillary nerve stimulation was made to allow comparison with initial readings.

We have shown:

Low amplitude stimulations of the axillary nerve in 6 of the 10 patients undergoing shrinkage.

We have concluded:-

Stimulation of the axillary nerve occurs frequently during capsular shrinkage.

We would like to acknowledge the Magstim Company for their assistance with this project.

The role of matrix metalloproteinases (MMPs) in the aseptic loosening of hip prostheses is well established. Gelatinase MMPs have been identified in the interface membranes and the pseudosynovial tissues in the hips. Little data are available on gelatinase MMPs and their major regulators, including specific tissue inhibitors of matrix metalloproteinases (TIMPs) in the loosening of shoulder prostheses. The objectives of this study were to determine whether A) gelatinase MMPs and their regulators (MMP14, TIMP-1,-2) are produced by periprosthetic tissues in cases of aseptic loosening of shoulder prostheses, and, B) to identify which cell types, in both interface and synovial tissues, localize the enzymes.

Interface tissues and synovial tissues were obtained during revision surgery for loose shoulder implants. In 9 patients (6-Total Shoulder Replacement, 3-Hemiarthro-plasty (Bipolar), 9 samples of interface tissues and 8 samples of synovial tissues were obtained. Of the interface tissues 2 were from the interface of the bipolar and the unresurfaced glenoid. Formalin-fixed paraffin embedded sections were stained using primary antibodies for MMP2 (Neomarkers), MMP9 (Oncogene Ltd), TIMP1, TIMP2 & MMP14 (Chemicon Ltd). Antigen retrieval required pressure cooker treatment for MMP2 and MMP9 and trypsin for TIMP1. Visualisation used a standard DAB chromagen technique (Envision, Dako Ltd.). Appropriate control sections ensured reproducibility of the staining. The antibodies selected bind to both active and inactive forms of the MMPs.

Both HDPE and metal debris were seen in both the synovial and interface tissues. Transformation of macrophages to giant cells was associated with PE debris, and was not observed with metal debris alone.

The presence of gelatinase MMPs in both interface and synovial tissues in aseptic loosening of shoulder prostheses was demonstrated. Differences between the MMP content of macrophages and giant cells between the tissues was detected, positivity was associated with the presence of metallic and/or HDPE debris. Activation of endothelial MMP2 by both MMP14 and low levels of TIMP2 would support the development of a vascular network.

The overall incidence of cuff tears increases with age, individuals over 80years having a 51% incidence of a tear. Currently, the aetiology of rotator cuff tears remains unclear and successful repair is achieved in only 30% patients. Matrix metalloproteinases (MMPs) have roles in a wide range of physiological processes including placentation and embryogenesis, tissue remodelling and wound healing. However, the ability of MMPs to dissolve extracellular matrix has been linked to a variety of pathological processes including rheumatoid arthritis, osteoarthritis, periodontitis and multiple sclerosis, which involve excessive matrix destruction. Production of gelatinase MMPs by torn rotator cuff has been demonstrated. The objectives of this study were to examine the expression of MMPs and their association with histological changes in full thickness tears of the rotator cuff.

Rotator cuff tissue was obtained from ten patients (age 40–80years) undergoing surgical repair. The size of tear was 1–4.5cm; time from presentation to surgery was 1 month (acute) to between 0.5–4years (chronic). Immunohistochemical staining with commercial monoclonal antibodies to a range of MMPs, endothelial, macrophage and fibroblast markers was performed. Production of gelatinase MMPs was measured by gelatin zymography on tissue culture supernatant. Visualisation used a standard DAB chromagen technique.

In the acute specimens there was an infiltrate of macrophages with little collagen degeneration; the fibro-blasts were MMP1 positive and endothelial cells MMP2 positive. At 12 months post-tear mature collagen, plump fibroblasts and proliferating endothelial cells were identified adjacent to the resection edge. Towards the torn edge areas of lower cellularity, sparse vascularity and collagen degeneration were observed. Vimentin positive, CD68 negative cells within this matrix were rounded with foamy cytoplasm, and intensely positive for MMP1 and MMP2, and positive for MMP-3, -10, -11, -13 and -14. Tissue culture supernatant demonstrated active and latent MMP2 production in all cases.

The prolonged interval between trauma and surgical repair, with potential pharmacological intervention, remedial physiotherapy and disuse immobility, make assessment of the factors contributing to tendon degeneration difficult to determine. Fatty infiltration, dystrophic calcification and patchy collagen degeneration were common. However, clear evidence of cellular activities typical of wound repair were also identified, including fibroblast and endothelial cell proliferation. The most striking finding was the association between areas of poor collagen structure with fibroblasts staining intensely for both MMP1 and MMP2 and positive for other matrix metalloproteinases. The production of MMP1 and MMP2 may contribute to active remodelling of the tendon matrix. Success of repair could be influenced by both the quality of the matrix and the cell types and activities in the tissue at the resection edge.

Purpose: To investigate the relationships between vascular endothelial growth factor (VEGF), a proliferation marker (Ki-67) and the cell cycle inhibitor p27 (cyclin-dependent kinase inhibitor p27), in endothelial cells in chronic degeneration of the rotator cuff.

Background: The rotator cuff is subject to constant pressure from the head of the humerus. This tends to ‘wring out’ the blood supply resulting in a functionally avascular critical zone, although microvessels can be identified. This zone is the site of degeneration and tears. Attempts at repair under these circumstances could be compromised by inadequate local function of the vascular system particularly sprouting of the capillaries to support the repair process.

Methods: Rotator cuff tissue was obtained from ten patients (age 40–80y) undergoing surgical repair. The size of tear was 1–4.5cm, time from presentation to surgery was 1 month (acute) to between 0.5–4y (chronic). Immunohistochemical staining with commercial mono-clonal antibodies to VEGF, p27, Ki-67 was performed on formalin fixed paraffin embedded tissues. Endothelial cells were identified by CD31 and smooth muscle actin (SMA) positivity. Visualisation used a standard DAB chromagen technique.

Results: Microvessel distribution varied according to tissue location, being pronounced towards the muscle insertion and torn edges of tissue, but much reduced in areas of healthy tendon and absent from areas with clear signs of advanced matrix degeneration without tears. Widespread VEGF positivity was observed in fibroblast and endothelial cell populations and diffusely within the matrix. Strong P27 positivity was observed in many endothelial cells which consequently demonstrated little Ki-67 staining.

Conclusion: Thus the endothelial cells appear to be simultaneously under both a mitogenic, VEGF drive, and subject to an inhibition of proliferation i.e. p27 positivity.