Aims

Hip and knee arthroplasty is commonly performed for end-stage arthritis. There is limited information to guide golfers on the impact this procedure will have postoperatively. This study aimed to determine the impact of lower limb arthroplasty on amateur golfer performance and return to play.

Background: Distinguishing septic arthritis from transient synovitis of the hip in children can be both crucial and challenging. In 1999, Kocher et al suggested four clinical predictors, fever > 38.5°C, inability to weight bear, WBC count > 12.0x109/L, and ESR> 40mm/hr; that, when combined were highly predictive of septic arthritis in children (99.6%). This figure was challenged by Luhmann et al, stating that the clinical prediction did not exceed 59%. In 2006, Caird et al recommended adding CRP of > 20mg/L as a fifth predictor.

Aims: To assess the value and accuracy of clinical prediction algorithms in distinguishing septic arthritis from transient synovitis of the hip in children in our hospital.

Methods: A retrospective review of all children admitted to our institution with painful hips was carried out over a period of four years (Feb 2003 to Mar 2007). One-hundred and twenty-two admissions (115 patients, 7 re-admissions) were reviewed.

Results: 79 patients (64.8%) were males. The mean age was 6 years (9 months to 15 years).

86 patients (70.5%) were diagnosed with transient synovitis. All the 7 re-admissions were from this group. Only one of the re-admissions was diagnosed with confirmed septic arthritis.

4 patients (3.3%) were diagnosed with definite septic arthritis with positive cultures from the hip, and 1 (0.8%) with probable septic arthritis (negative culture).

The presence of the clinical predictors was compared between the transient synovitis and septic arthritis groups, using Fisher’s exact test. Only the raised temperature and CRP were found to be significantly different (p< 0.05).

Only two children (40%) with confirmed septic arthritis had four or more predictors (one had all five, and the other was able to partially weight bear). The third child had a raised temperature and CRP, and the fourth had a raised temperature only. The fifth patient (20%) was diagnosed with probable septic arthritis. His cultures were negative, but he was already on intravenous antibiotics. This patient did not have any of the predictors on admission (temperature was 38.3°C, CRP 10.7). However, he spiked a temperature of 40°C 24 hours post admission despite being on antibiotics, and his CRP increased to 34.5mg/L.

In the transient synovitis group, two patients (2.2%) had positive five predictors, but were proven to have transient synovitis secondary to a urinary tract infection and gastroenteritis. 47 patients (51.6%) did not have any of the predictors, and 6 patients (6.6%) had three or more positive predictors.

Conclusion: Although clinical predictors are helpful in distinguishing septic arthritis from transient synovitis, there were false negative and false positive findings in the study. The predictors cannot be considered alone, and ultimately clinical judgement must be exercised to ensure that cases of septic arthritis are not missed.

The purpose of the study was to determine how suture materials commonly used in arthroscopic surgery were affected by electrocautery. The effects of electrocautery were evaluated on four different suture materials commonly used in arthroscopic surgery; PDS, Ethibond, Orthocord and Fibrewire. Single suture strands were tied around two plastic rods immersed in a saline filled water bath at 37°C. Sutures were exposed to heat using the Mitek VAPR 3 electrosurgical unit and a corresponding side electrode. This was used on the high intensity vaporisation setting, at a power level of 240W. The electrode was applied directly to the suture strand, under tension, until the strand was completely burnt through. Fibrewire demonstrated a significantly higher burn through time in comparison to the other materials tested (83.30±38.69s, p< 0.001). Orthocord also demonstrated high heat tolerance (38.96±12.64s), which was significantly higher than both PDS (1.61±0.25s) and Ethibond (0.93s±0.06s) (p< 0.001). This is the first study to our knowledge assessing the tolerance of suture materials to electrocautery. This has important implications for the arthroscopic surgeon. On completion of an arthroscopic repair, the surgeon must always be extremely cautious, for fear of damaging the suture material and compromising their soft tissue repair. This study demonstrates that both Fibrewire and Orthocord can tolerate prolonged, direct heat application from electrocautery. We therefore conclude that short bursts of soft tissue vaporisation, after completing an arthroscopic repair with Fibrewire or Orthocord, are unlikely to have a detrimental effect on the suture material. However care should be exercised by the surgeon using Ethibond or PDS.

The study objective was to assess if the mechanical properties of Polylactic Acid (PLA) bio-absorbable suture anchors vary with temperature? Bio-absorbable suture anchors may offer advantages over metal anchors. However, their performance at body temperature has been questioned in recent literature (Meyer et al). In particular, constant tension at body temperature caused early failure at the anchor eyelet. Using a previously validated mechanical jig, 15 standard locked sliding arthroscopic knots (Duncan Loop + three alternate hitches) were tied by the senior author using PAN-ALOK anchors (DEPUY MITEK, Edinburgh, UK) and ETHIBOND sutures (ETHICON) and placed under a standard constant tensile load reproducing the action of the surgically repaired rotator cuff. All anchors were loaded for at least five days to match previous studies. Eight were incubated at a constant 37°C and six were kept at room temperature. The elongation of the suture knot/anchor construct was assessed by a rheostat within the mechanical jig. Sample unused, room temperature and body temperature anchors were blindly analysed using plane polarized light microscopy with a graticule to assess deformation, concentrating on the eyelet region. Mean elongation of body temperature anchors = 0.461mm (0.159 – 0.952) Mean elongation of room temperature anchors = 0.278mm (0.159 – 0.793) Unpaired t-test: p=0.24 Microscopic analysis of the anchor material showed no difference in structural deformation in the three anchors. Our model suggests no significant increase in elongation at body temperature for this commonly used arthroscopic suture anchor / knot construct. This counters previous work. It gives us confidence to continue to use such devices.

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.

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.

Surgeons often protect Tendon-bone reconstructions such as rotator cuff repairs by off loading them. We investigated the effect of limb position and boundary conditions in an in-vitro rabbit patella tendon-bone repair model. Patella tendons were repaired back to the tibia in eight hindlimb cadavers with 2 mitek anchors(Mitek, Westwood, MA) and 3-0 Ethibond (Ethicon, Sommerville, NJ) using two techniques, one involving simple sutures and the other involving crossing over between the sutures. A loading mechanism through the patella tendon was constructed using static weights over a pulley mechanism. The contact area and force at the PT-bone interface were measured using a TekScan pressure sensor (6911, TekScan, South Boston, MA). The contact footprint (area and normal force) was acquired under four configurations: (1) knee full extension with interface unloaded, (2) knee 45° flexion with interface unloaded, (3) knee full flexion with interface loaded by limb weight alone, (4) tendon loaded with limb weight and 20N force applied through tendon loading mechanism. The contact area force footprint changed substantially between the different suture techniques and loading configurations. Crossing over of sutures appears to provide an increased and more evenly distributed force across the tendon-bone interface. Repair off-loading was accompanied by a decrease in the contact footprint force and pressure. The force in both suture techniques increased with increasing flexion angle and was substantially increased by both bearing the weight of the dependent limb and by an axial load in the patellar tendon. Off loading a repair may not provide optimal environment for healing.

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.