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Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_16 | Pages 9 - 9
17 Nov 2023
Lim JW Ball D Johnstone A
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Abstract

Objectives

Acute compartment syndrome (ACS) is a progressive form of muscle ischaemia that is a surgical emergency and can have detrimental outcomes for patients if not treated optimally. The current problem is that there is no clear diagnostic threshold for ACS or guidance as to when fasciotomies should be performed. A new diagnostic method(s) is necessary to provide real-time information about the extent of muscle ischaemia in ACS. Given that lactic acid is produced by cells through anaerobic respiration, it may be possible to measure H+ ion concentration and to use this as a measure of ischaemia within muscle. Although we are familiar with the key biochemical metabolites involved in ischaemia; and the use of viability dyes in cell culture to distinguish between living or dead cells is well recognised; research has not been undertaken to correlate the biochemical and histological findings of ischaemia in skeletal muscle biopsies. Our primary aim was to investigate the potential for viability dyes to be used on live skeletal muscle biopsies (explants). Our secondary aim was to correlate the intramuscular pH readings with muscle biopsy viability.

Methods

Nine euthanised Wistar rats were used. A pH catheter was inserted into one exposed gluteus medius muscles to record real-time pH levels and muscle biopsies were taken from the contralateral gluteus medius at the start of experiment and subsequently at every 0.1 of pH unit drop. Prior to muscle biopsy, the surface of the gluteus medius was painted with a layer of 50µmol/l Brilliant blue FCF solution to facilitate biopsy orientation. A 4mm punch biopsy tool was used to take biopsies. Each muscle biopsy was placed in a base mould filled with 4% ultra-low melting point agarose. The agarose embedded tissue block was sectioned to generate 400 micron thick tissue slices with a vibratome. The tissue slices were then placed in the staining solution with Hoechst 33342, Ethidium homodimer-1 and Calcein am. The tissue slices were imaged with Zeiss LSM880 confocal microscope's Z stack function. A dead muscle control was created by adding TritonX-100 to other tissue slices. For quantitative analyses, the images were analysed in Image J using the selection tool. This permitted individual cells to be identified and the mean grey value of each channel to be defined. Using the dead control, we were able to identify the threshold value for living cells using the Calcein AM channel.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_16 | Pages 10 - 10
17 Nov 2023
Lim JW Ball D Johnstone A
Full Access

Abstract

Background

Progressive muscle ischaemia results in reduced aerobic respiration and increased anaerobic respiration, as cells attempt to survive in a hypoxic environment. Acute compartment syndrome (ACS) is a progressive form of muscle ischaemia that is a surgical emergency resulting in the production of Lactic acid by cells through anaerobic respiration. Our previous research has shown that it is possible to measure H+ ions concentration (pH) as a measure of progressive muscle ischaemia (in vivo) and hypoxia (in vitro). Our aim was to correlate intramuscular pH readings and cell viability techniques with the intramuscular concentration of key metabolic biomarkers [adenosine triphosphate (ATP), Phosphocreatine (PCr), lactate and pyruvate], to assess overall cell health in a hypoxic tissue model.

Methods

Nine euthanised Wistar rats were used in a non-circulatory model. A pH catheter was used to measure real-time pH levels from one of the exposed gluteus medius muscles, while muscle biopsies were taken from the contralateral gluteus medius at the start of the experiment and subsequently at every 0.1 of a pH unit decline. The metabolic biomarkers were extracted from the snap frozen muscle biopsies and analyzed with standard fluorimetric method. Another set of biopsies were stained with Hoechst 33342, Ethidium homodimer-1 and Calcein am and imaged with a Zeiss LSM880 confocal microscope.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_7 | Pages 3 - 3
1 May 2019
MacDonald D Caba-Doussoux P Carnegie C Escriba I Forward D Graf M Johnstone A
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The aim of our study was to compare the incidence of post-operative anterior knee discomfort after anterograde tibial nailing by suprapatellar and infrapatellar approaches.

95 subjects presenting with a tibial fracture requiring an intramedullary nail were randomised to treatment using a suprapatellar (SP) or infrapatellar (IP) approach. Anterior knee discomfort was assessed at 4 months, 6 months and 1 year post operatively using the Aberdeen Weightbearing Test-Knee (AWT-K), knee specific patient reported outcome measures and the VAS pain score. The AWT-K is an objective measure which uses weight transmitted through the knee when kneeling as a surrogate for anterior knee discomfort.

53 patients were randomised to an SP approach and 42 to an IP approach. AWT-K results showed a greater mean proportion of weight transmitted through the injured leg compared to the uninjured leg when kneeling in the SP group compared to the IP group at all time points at all follow-up visits. This reached significance at 4 months for all time points except 30 seconds. It also reached significance at 6 months at 0 seconds and 1 year at 60 seconds.

We conclude that the SP approach for anterograde tibial nailing reduces anterior knee discomfort post operatively compared to the IP approach.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_3 | Pages 12 - 12
1 Feb 2014
Munro C Johnstone A
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This prospective Randomised Controlled Trial compared two surgical approaches with respect to accuracy of guidewire and tibial nail position.

Sixty-seven patients with tibial fractures were randomised to semi-extended (SE) or standard (S) approaches of nail insertion. Fluoroscopy was performed at guidewire insertion and final nail position. The SE approach is more proximal with the guidewire inserted posterior to the patella, theoretically allowing a better angle for more accurate nail placement.

Measurements were taken in the Anteroposterior and lateral planes of both the nail and guidewire to determine deviation from the optimal angle of insertion (relative to the long axes of the tibial shaft). Thirty-nine and twenty-eight patients were treated with semiextended and standard approaches respectively.

The semiextended approach resulted in improved nail placement to statistical significance in both planes, with mean deviation from the optimal angle of insertion as below:

Guidewire AP 3.2° (SE) versus 4° (S) Lateral 27.1° (SE) versus 30.2° (S)

Nail AP 2.4° (SE) versus 4.2° (S) Lateral 17.9° (SE) versus 21.8° (S)

Poor positioning of the guidewire leads to excessive anterior placement of the nail by eccentric reaming. Anterior positioning of the guidewire and nail in the lateral plane was assessed. This was expressed as a percentage from the anterior cortex of the tibia.

Guidewire: Lateral 9.7% (SE) versus 9.3% (S)

Nail: Lateral 23.4% (SE) 19.3% (S) (p 0.043)

Semiextended nailing allows a better angle for guidewire placement and a more optimal final nail position. This facilitates accurate nail placement particularly in difficult proximal third fractures.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_16 | Pages 38 - 38
1 Apr 2013
Johnstone A Johnstone AJ Elliott KG
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Failure to treat acute compartment syndrome (ACS) early leads to significant morbidity. Current practice depends on using clinical signs and intracompartmental pressure (ICP) monitoring to diagnose the syndrome but there is still debate regarding their accuracy and interpretation.

Patients admitted with injuries at risk of ACS underwent intramuscular (IM) pH and ICP monitoring combined with regular clinical assessment. Fasciotomies were performed on those with clinical and/or pressure based evidence of ACS. All patients were subsequently assessed for evidence of a missed ACS at at 6 & 12 months.

Of the 62 patients, 51 completed the protocol and were included in the analysis. They were divided into 2 groups: those who had ACS, either initially (fasciotomies; 13), or diagnosed at follow up (no fasciotomies; 7), and those with no evidence of ACS (31).

The sensitivity and specificity for the worst values for each variable were calculated and receiver operator characteristic (ROC) curves generated. The area under the curve for pH was 0.92, 0.73 for absolute pressure and 0.59 for delta pressure. To achieve a sensitivity of 95%, an absolute pressure of >30mmHg was 30% specific, a delta pressure of <33mmHg was 27%, while IM pH of 6.38 was 80% specific.

This study highlights the issues concerning current diagnostic methods for ACS. By comparison, IM pH radically out performed both the highest ICP and the lowest delta pressure, identifying patients early and accurately.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_16 | Pages 42 - 42
1 Apr 2013
Medlock G Wohlgemut J Stevenson I Johnstone A
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Intro

Distal radial fractures are a commonly encountered fracture & anatomical reduction is the standard. Dorsal angulation is the traditional method of assessment but is inaccurate in rotated lateral xrays. Previously a relationship has been demonstrated between the dorsal cortex (DC) of the radius & the superior pole of the lunate (SL) & its sensitivity for assessing dorsal angulation & translation.

Hypothesis

A constant anatomical relationship maintained between the DC and the SL when rotated up to 30 degrees from standard lateral?


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 346 - 346
1 Sep 2012
Baliga S Carnegie C Johnstone A
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Introduction

Several clinical and radiological studies have confirmed the benefits of using Volar Locking Plates (VLPs) to treat unstable distal radius fractures. The “theoretical” advantage of VLPs compared to standard plate fixation is that VLPs, through their design, intrinsically provide angular stability for most fracture configurations including comminuted fractures and, quite possibly, osteoporotic fractures. However few studies have compared the clinical results of patients of different ages who have been treated using VLPs.

Aim

The aim of this study was to compare the clinical outcomes of VLP fixation of displaced distal radius in younger (<59 yrs) and older (>60yrs) patients.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXIX | Pages 136 - 136
1 Sep 2012
Munro C Baliga S Johnstone A Carnegie C
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Volar Locking Plates (VLP) have revolutionised the treatment of distal radius fractures allowing the anatomic reduction and stable fixation of the more comminuted and unstable of fractures. The benefits of this in terms of range of movement (ROM), pain and earlier return to work and daily activities is documented. However we were interested in was what improvements in wrist function patients made from 6 to 12 months after injury?

Methods

We retrospectively looked at a series of 34 consecutive patients that had undergone VLP fixation through a standard anterior approach followed by early physiotherapy. We documented standard demographics and assessed function in terms of Range of Movement, Grip strength (GS), Modified Gartland and Werley score (MGWS), Patient Rated Wrist Evaluation (PRWE) and the quick DASH questionnaire at six and twelve months

Results

Two patients were excluded from analysis as they failed to make both assessments. Of the 32 remaining (26 female:6 male) the mean age was 53.2yrs; range (26–78). On average GS, PGS, VAS function and pain did not improve. There was a modest improvement in Movement; Wrist Flexon-13 deg, Wrist Extension-14deg, Radial Deviation-7deg, Ulnar Deviation-9deg. There was no improvement in pronation and supination.

There was little improvement in qDASH, PRWE and mGW Scores with only a mean 1.8, 5.6 and 3.6 point improvement respectively.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XVII | Pages 35 - 35
1 May 2012
Baliga S Johnstone A McKenna S
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Background

Angular stable volar locking plates have become increasingly popular for more comminuted fractures of the distal radius. Newer designs of plates have been thicker in profile and incorporate more options for distal fragment fixation. Although they have been shown to be successful at maintaining reduction to allow early mobilisation the main drawback is from screw cut-out. In our practice we have noticed that the newer style of plates that offer more rigid fixation has lead to more instances of screw cut-out. We aimed to quantify the minimum number of locking pegs and or screws need to maintain the operative reduction.

Method

We retrospectively looked at a series of 46 patients that had undergone volar plating. We assessed the fracture severity on pre-operative films (according to AO classification) and compared radiographic parameters (volar tilt VT, radial inclination RI and radial height RH) on post-operative films. We calculated the amount of reduction lost from initial post operative x-rays to radiographs taken when union was confirmed. We compared this to the number of locking units used to fix the distal radius and also the configuration they were inserted, i.e. the number in the radial and middle columns.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_V | Pages 4 - 4
1 Mar 2012
Karuppiah S Downing M Broadbent R Christie M Carnegie C Ashcroft G Johnstone A
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Due to its popularity of intramedullary nails (IMN) high success rate, newer design (titanium) IMN system have been introduced to replace stainless steel system. However the stability provided by the titanium IMN

may not be adequate, there by influencing the union rate.

We aimed to compare the results of both IMN systems via prospective clinical study and biomechanical testing using RSA.

Biomechanical study

This study was done in an experimental set-up which consisted of a physically simulated femoral shaft fractures models fixed with a stainless steel (Russell Taylor) or Titanium (Trigen) IM nailing system. Two common fracture configurations with stimulated weight bearing conditions were used and the axis of fragment movements recorded.

Clinical study

The data on two groups of patients were collected as part of a prospective cohort study. Details of the implant, such as size of nail, cross screw lengths, screw thickness, etc. was collected. Patients were followed up for a minimum of 4 months and details of clinical complications recorded


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_III | Pages 136 - 136
1 Feb 2012
McCullough L Carnegie C Christie C Johnstone A
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Despite the variety of implants or techniques that exist to treat displaced distal radial fractures, the majority fail to provide sufficient stability to permit early functional recovery. However, locking plates have the advantage over other implants in that locking screws add considerably to the overall stability.

The aim of this study was to assess the functional outcome of patients with displaced distal radial fractures treated with a volar distal radial locking plate (Synthes).

During a two year period, details of 98 patients admitted to our unit with inherently unstable dorsally displaced distal radial fractures treated with volar locking plates were collected prospectively. For the purpose of this analysis, only those patients (55) with unilateral fracture, able to attend the study clinic at 6 months post-injury were considered. Patients were immobilised in wool and crepe for a 2 week period.

The group consisted of 15 males and 40 females with an average age of 54 (28 to 83). At 6 months, patients' perceived functional recovery averaged 80%. Objective assessment was considered in relation to the uninjured side: grip strength 73%; pinch strength 83%; palmarflexion 77%, dorsiflexion 80%; radial deviation 74%; ulnar deviation 74%; pronation 93%, and supination 92%. Seven patients complained of symptoms relating to prominent metalwork.

Good/excellent early subjective and objective functional recovery was made following open reduction and internal fixation using volar locking plates of dorsally displaced distal radial fractures. We suggest that objective assessment of grip strength and dorsiflexion can be used as a measure of patient perception of function.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 213 - 213
1 May 2011
Mcgrath A Kalson N Johnstone A
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Viscosupplementation with hyaluronic acid (HA) is an established intervention for pain control in patients with mild to moderate osteoarthritis (OA) of the hip and knee. It is highly concentrated at the surface of the articular cartilage and the superficial layers of the synovial membrane. In the synovial fluid, HA acts as both a lubricant and a shock absorber. Due to the meshwork it forms with aqueous solutions, it acts as a semi-permeable barrier regulating metabolic exchanges between cartilage and the synovial fluid, and a viscoelastic shield around synoviocytes and adjacent nerve endings. Through its molecular size HA hinders the free movement of lytic enzymes and inflammatory mediators, and enhances chondrocyte metabolism. Osteoarthritis is associated with a decrease in concentration and average molecular weight of native HA in synovial fluid.

The mechanism of action of administered intra-articular HA is not completely understood, but as its clinical benefit exceeds its intra-articular presence, it is thought to perhaps induce native biosynthesis of HA and other extracellular matrix components and in particular suppress the inflammatory response and inhibit substance P, in addition to contributing to shock absorption by means of its viscoelastic properties.

Problems include inconvenience, expense and the logistical problems associated with multiple injections, injection technique and level of skill required by the administering physician, variable clinical response and adverse reactions.

In this independent, prospective, randomized trial, we compare efficacy and complications associated with treatment 100 athletes (112 knees) using durolaneTM and synvisc oneTM using the Visual Analogue Score, SF-36 V2 questionaire, and Oxford knee scores. Range of movement and absence from sporting activity is recorded at each visit. These assessments are repeated at 3, 6, 9 and 12 months. Significant improvement is seen in the VAS, SF 36 V2 and Oxford Knee Scores (p=0.01) and reduction in the use of analgesics and anti-inflammatories is seen with both products at 3 months post injection, with a significant advantage to the duro-lane group (p=0.001). At 6 months, this difference is extended even further. A small but statistical difference is noted in the time taken for the athlete to return to sporting activity following a rest period due to pain. Adverse reactions occur significantly less with the more effective product. We conclude that intra-articular HA a useful intervention in patients with mild to moderate OA of the knee, can produce sustained pain relief at 6 months, and can reduce the requirement for analgesia and anti-inflammatory medication during this time.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 167 - 167
1 May 2011
Johnstone A Carnegie C Christie E
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Introduction: In recent years both patients and clinicians have benefitted from using volar locking plates (VLPs) to treat otherwise difficult to stabilise displaced distal radius fractures. However, it is not clear whether the newer VLP systems offer real clinical advantages over the original systems. AIM: To assess the clinical outcome of patients treated using two VLP systems.

Methods: Two cohorts of patients treated with a distal radius VLP were assessed prospectively by an independent assessor at 6 months following surgery using Visual Analogue Scales (pain & function), range of movement, grip and pinch strength. Complications were also recorded. 68 patients treated with the original Synthes VLP and 51 with a Periloc VLP (Smith & Nephew) were available for clinical review. There were no differences in patient demographics or injury types between the groups.

Results: Treatment with both VLP systems resulted in good or excellent clinical outcomes for both patient groups. Using either the median or the mean results, there were no differences between either of the VLP groups with respect to pain, subjective function, grip or pinch strength, palmar flexion, dorsiflexion, radial or ulnar deviation, or forearm rotation. The complication rates were also very similar, the most common problem relating to prominent metal work necessitating removal after fracture healing in 7 – 9% of out patients. Conclusion: VLPs are excellent implants for restoring wrist function and reducing longterm symptoms. The potential advantages of the newer generation of VLPs over the simpler original VLP designs remain unproven.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 579 - 580
1 Oct 2010
Johnstone A Carnegie C
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In recent years volar locking plates (VLP) have revolutionised the treatment of more complex distal radial fractures, but doubt still exists as to whether this is an operation for all suitably qualified orthopaedic surgeons, in particular experienced trainees, or remains the domain of consultants or better still upper limb surgeons.

Aims: To assess changes in a Level 1 Trauma Unit’s practice over a 5 year period and to compare the clinical outcomes of patients operated upon by experienced orthopaedic trainees and consultant surgeons.

Methods: Two prospective cohort studies were undertaken using (a) the Synthes VLP (January 2003–January 2005), and (b) the Periloc (Smith & Nephew) VLP (January 2007–February 2008). All patients were assessed at 6 months following surgery for range of movement, grip and pinch strength, and subjective levels of pain and function using Visual Numerical Scales. 65 and 36 patients were available for 6 month review in the Synthes and Periloc groups respectively. Operations undertaken by, or assisted directly by, the consultant were considered to be ‘consultant’ procedures, with all others being undertaken by trainees.

Results: No significant patient demographical differences, or differences in fracture type were identified for the two cohorts. Clinical outcomes for the two cohorts were likewise similar at 6 months although there was a suggestion that pain, pinch and grip strength were marginally better in the Periloc group although this was not statistically significant. In the Synthes VLP cohort, 32 operations were undertaken by consultants and 33 by trainees, compared with 9 and 27 operations being undertaken by consultants and trainees respectively in the Periloc group. Although there was a tendency for the more difficult fractures to be operated upon by consultants, especially in the earlier cohort, trainees were left to deal with many of the more complex injuries in the Periloc cohort. The incidence of minor complications requiring further surgery (all relating to prominent metalwork) was also low in both groups (7 in the first group and 2 in the second group) with all but one of the index operations having been performed by a trainee.

Discussion: Despite the complexity of many distal radial fractures, VLP treatment of distal radial fractures has become a common place procedure that, in our unit, are frequently left to experienced trainees to operate upon without supervision. Our prospectively cohort studies clearly show that, over time, experienced trainees obtain clinical results that are similar to their consultant colleagues with respect to clinical outcome and incidence of complications.

Conclusions: As our unit’s experience of treating patients with distal radial fractures with VLPs has grown, experienced trainees appear to obtain clinical results that are similar to consultants.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 572 - 572
1 Oct 2010
Johnstone A Christie E
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Proximal Humeral fractures are common injuries that are difficult to treat satisfactorily despite the variety of operative and conservative treatment options that are available. To make any real sense of the literature concerning the treatment of these injuries, it is important that the tools that clinicians use to assess clinical outcomes accurately reflect each patient’s level of symptoms and function.

Aim: To assess how well commonly used subjective, and composite clinical scoring systems reflect patients’ perceptions of pain and functional recovery.

Methods: We invited all patients who had sustained a proximal humeral fracture that had been treated using a PHILOS (Synthes) Locking plate to attend for review. All patients were reviewed at a minimum of 14 months following surgery by which time they had all been discharged from regular clinical review months before. All patients completed subjective Visual Numerical Scales (VNSs) for pain, and for function, that were used to compare more commonly used shoulder/upper limb scores (UCLA, Modified Constant, Oxford, and Quick DASH scores).

Results: 33 patients were available for review. 55% were women. Age range 25–83 years (Ave. 57 years). Timing of review after index procedure (Range 14–58 months, ave. 30 months). Patients appeared to find the numerical VNSs easier to understand, and interestingly, analysis of the pain component of the each of the commonly used scores were answered inconsistently when the scores were compared. With respect to patient perception of pain and subjective level of function, both the Oxford and Quick DASH scores consistently overscored both parameters placing the majority of patients in higher (clinically better) categories, while the Constant score underscored the majority of patients placing them in lower categories (satisfactory or poor). The UCLA score was marginally better than the Constant score in relation to the VNSs for pain and function.

Discussion: Despite our dependence upon the more commonly used Clinical Outcome Scoring systems to help guide us with choosing the best treatment options for our patients with proximal humeral fractures, our study confirms our suspicions that none of these outcome scores truly reflect our patients perception of function and pain. In addition, the terminology and sentence structure that is used in all of the commonly used scoring systems may bias the results by confusing many of our patients.

Conclusion: Currently, none of our commonly used shoulder outcome scores truly reflect the clinical outcome of patients who have sustained proximal humeral fractures. Instead, it may be better to use subjective VNSs that are easy for patients to understand and are quick to use.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 550 - 550
1 Oct 2010
Johnstone A Carnegie C Christie E McCullough A
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Despite advances in Locking Plate (LP) design, distal femoral fractures remain challenging injuries to treat especially in the elderly where approximately 15–30% develop nonunions secondary to failure of fixation.

Aim: To establish the mechanisms of nonunion in our patient population using two different LP systems.

Methods: Between December 2002-May 2008, we prospectively collected data on all 67 patients with distal femoral fractures who were treated using a suitable distal femoral LP (LISS, 35 cases, or Periloc, 32 cases). 72% of the patients were female; ages ranged from 25–94 years (ave. 67 years). Many of our patients had a number of significant co-morbidities.

Results: The presence of significant co-morbities e.g. Rheumatoid arthritis, long term systemic steroid use, cerebrovascular accidents resulting in ambulatory problems, previous major joint arthroplasty including ipsilateral knee replacements, paralysis, and severe dementia, did not appear to influence fracture union significantly. However, old age was strongly correlated with nonunion with all failed cases (7 patients - 10% of the study group) presenting with failure of fixation. 2 of the LP system failures resulted in malunion and the 5 other cases required revision surgery. Of note, all 7 patients were elderly, 6 being over 80 years of age. The mechanism of fixation failure was specific to each of the LP systems. All 4 of the failures treated with LISS, resulted from poor proximal stability as a consequence of unicortical screw fixation. Two patients required to have the proximal fixation revised through the insertion of bicortical screws which subsequently resulted in successful union. The other two patients were treated in long leg casts as the varus deformities were considered acceptable given each patient’s needs. All 3 of the failures who had been treated with a Periloc LP, resulted from fracturing of the plate at the metaphyseo-diaphyseal junction at the level of the main extra-articular component of the fracture. The plates all fractured through the unfilled screw holes, and all 3 patients required revision of fixation to bring about union.

Discussion: The LISS failures can all be attributed to poor proximal fixation that is associated with the use of unicortical screws in osteoporotic bone and confirms the need for bicortical screw fixation. However, modern LP systems manufactured from stainless steel offer increased implant stability that may in turn stress any fracture bridging segments of the LP.

Conclusion: Although we are aware of the importance of bicortical screws in osteoporotic patients, it is also seems likely that excessive plate rigidity should be avoided, by using long plates with well spaced out screws.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 550 - 550
1 Oct 2010
Johnston A Carnegie C Christie E Johnstone A Mccullough A
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Aim: The use of volar plates in the management of distal radius fractures has increased dramatically over the last decade. Our aim was to ascertain if long term outcome could be predicted at clinical review four months following operation.

Patients and Methods: Between January 2003 and January 2005, all patients presenting with unilateral distal radius fractures and treated with volar locking plate fixation (Synthes) were invited to participate in long-term follow up. The decision to use a volar plate and the operative procedure itself was undertaken by the on-call consultant and his team. Patients who agreed to enter the study were evaluated at 4, 6 and 12 months following operation. Patient demographics, hand dominance and fracture type were recorded. Assessment of grip strength and wrist movements were undertaken and expressed as a percentage of the contralateral, uninjured side.

Results: A total of 76 out of 100 eligible patients agreed to participate in the study. Of those patients, 23 (30%) failed to attend all their follow-up appointments, leaving a dataset of 53 patients (70%) available for analysis. There were 28 females (53%) and the mean patient age was 55 years (range 28–83).

Grip strength, pinch grip, wrist flexion, wrist extension, radial deviation, ulnar deviation, pronation and supination all showed graded improvement in the year following fracture, achieving a mean range of 73% to 95% of function compared to the contralateral side at 12 months. Wrist flexion and ulnar deviation showed near maximum improvement by 6 months, whereas the other variables continued to show significant improvement between 6 and 12 months.

Logistic regression analysis suggested that improvement in wrist extension at four months was the best predictor of a good outcome at one year.

Discussion: Use of volar plate fixation is an increasingly common method of managing distal radius fractures. Our study suggests that good functional results can be achieved by this method of treatment. Failure to regain reasonable wrist extension by four months appears to predict higher risk of poor outcome and therefore patients in this group should be followed up more closely.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_II | Pages 357 - 358
1 May 2010
McGrath A Johnstone A
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Hip fracture is a common serious injury in the elderly. Between 1982 and 1998 the number of hip fractures reported annually in Scotland in patients over 55 years rose from 4,000 to 5,700. The optimum method of treatment for the various fracture types remains in contention. The purpose of this study was to compare outcome measures between displaced, intracapsular fractures in patients over 70 years fixed with cannulated screws and sliding hip screw with side plate. Between 1998 and 2005 a total of 30,482 patients were reviewed by the Scottish Hip Fracture Audit (SHFA). Of these 15,823(53.3% of the total) had sustained intracapsular fractures. 13,587 of these occurred in patients aged 70 or over. Of these 2,428 had undisplaced and 11,159 displaced fractures. We performed a Chi test statistical analysis comparing outcome measures in this group of displaced intracapsular fractures with respect to aspects of early failure. 534(3.9%) of patients were treated conservatively. 509 (4.7%) fractures were fixed using cannulated screws and 499 (4.6%) using a sliding hip screw. Readmission within 120 days for any cause occurred in 62 patients(14.1%) treated with cannulated screw fixation and in 63 patients(15.7%) for those treated with a sliding hip screw(P=0.509). Of these 36 patients(8.2%) in the former and 23 patients(5.7%) in the latter group were readmitted for complications related to hip fracture(P=0.033). Mortality within this period included 69 patients(13.5%) in the CS and 98(19.6%) in the SHS group. In terms of re-operation within 120 days of the original admission, 53 patients(10.6%) receiving cannulated screws compared to 24 patients(4.8%) treated with a sliding hip screw requiring further surgery(P=0.0006). The fracture was seen to displace in 12(22.6%) patients originally treated with cannulated screws compared to 6 patients(25%) treated with sliding hip screw(P=0.156). More significantly the fixation device was seen to have migrated in 24(45.3%) of the cannulated screw as compared to 7(29.2%) patients in the sliding hip screw group(P=0.002). Periprosthetic fractures were recorded in 4(7.5%) of the former and 3(12.5%) in the latter group(P=0.708). Wound infection was higher in the SHS group(2 patients) as compared to the screw fixation group(1 patient)(P=0.565). Statistical analysis demonstrates a dramatic difference exists between these 2 fixation types in terms of re-operation within 120 days of the original admission for which published literature has previously only recorded biomechanical, in vitro comparisons. Data regarding specific implant factors such as number of screws, position, configuration, starting point, thread length and use of washers in cannulated screws, and position, tapping, supplementary screw and compression screw in sliding hip screws was not recorded and may be considered to bias our results.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 471 - 471
1 Sep 2009
Johnstone A Karuppiah S
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Introduction: Current existing joint designs, principally flexible silastic spacers, satisfy the initial requirements but commonly lack durability. In particular all flexible silastic joints are prone to early breakage due to abrasion against bone and constant loading of the central section of the flexible implants. The aim of our new small joint design is to overcome many of the deficiencies of the flexible silastic designs while maintaining their main advantage of stabilising joint alignment throughout the flexion range.

Aim: To investigate the wear properties of the new small joint design in both static and dynamic applied loads using finite element analysis (FEA).

Materials: The design is essentially a cross between a flexible spacer and a surface replacement, whereby the spanning flexible spacer is located within the long axes of direct load bearing metacarpal and phalangeal ‘housings’. We have investigated a number of parameters, using finite element analysis (FEA), focussing principally upon the load bearing and wear properties of the new design to both static and dynamic applied loads with reference to the test protocol developed by the Durham group.

Results: Detailed FEA of the new joint design has highlighted the extreme potential durability of the housings and the internal flexible spacer. Our results suggest that the wear characteristics of both housings manufactured from PEEK (Polyetheretherketones) may result in the generation of considerably less wear debris compared with conventional alloy/plastic articulations. In addition, polyurethanes would appear to have better load bearing and wear characteristics than existing silastic materials.

Conclusions: Clearly, if our FEA findings were to be reproduced with biomechanical testing, we would be well placed to introduce durable and readily affordable small joint arthroplasties that may well resolve our current difficulties of treating patients with moderate joint disease in addition to being a realistic alternative for patients with advanced destructive small joint arthritis.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 472 - 472
1 Sep 2009
Johnstone A Karuppiah S
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Introduction: The current techniques used for locking the distal end of intramedullary nails with cross screws remain a technical operative challenge for many clinicians. The surgeon uses his/her experience and judgement to locate the distal holes in the intramedullary nail, relying heavily on the use of two dimensional intra operative X-ray images (fluoroscopy) to undertake a three dimensional task. As a result, a large number of X-ray images are frequently required, significantly increasing the radiation exposure to both the patient and the operative team. Also there is an overall proportional increase in the operating time.

Aim: We aimed to develop a simple new radiological alignment jig that would allow the accurate placement of distal locking cross screws during intramedullary nailing, with minimal radiation exposure and without having to visualise the distal screw holes.

Materials and method: Laboratory tests were conducted using plastic femora (Sawbones Limited) fixed with intramedullary nails. Tests were performed three times using each of the different femoral intramedullary nails (Russell-Taylor, Smith & Nephew) investigating whether the length or diameter of the nail had any influence upon the accuracy of distal screw insertion. After successfully concluding the laboratory tests, a limited clinical study was conducted using the new alignment jig to insert distal locking screws in patients.

Results: Both the bench tests and limited clinical study were 100% successful and permitted the clinician to identify the distal holes correctly without needing to visualise the distal screw holes radiologically.

Conclusion: Our initial bench tests and clinical study show that the new alignment jig allows simple and accurate insertion of the distal locking screws with minimal radiological guidance. It also has considerable potential to reduce the overall operating time.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 178 - 179
1 Mar 2009
Stevenson I Johnstone A
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Restoration of normal anatomy following a distal radial fracture is an important factor in determining functional recovery. However, current methods of assessing dorsal tilt and displacement require ‘true’ lateral radiographs, and important reference points are often obscured by metalwork.

Aims: To investigate if an easily identifiable and predictable relationship exists in the normal wrist between the distal radius and lunate; and if so, to compare fractured wrists (pre and postoperatively)using conventional and new assessment methods.

Methods: 22 patients with displaced distal radial fractures treated by ORIF, were included. Patients had pre and postoperative radiographs taken of the injured and uninjured wrists. From true lateral radiographs, measurements were performed using the PACS system. A line was superimposed upon the dorsal radial cortex at least 2cm proximal to the wrist and extending distally. The following measurements were performed: lunate height, distance from the ‘line’ to the superior and inferior poles of the lunate, and conventional measurements of dorsal tilt and angulation.

Results: Uninjured wrist: Most noticeably the dorsal radial line always passed superior to the lunate, mean distance of 3.27mm (1.75–6.6mm). As a ratio, the distance from the line to the superior pole of the lunate divided by the distance to the inferior pole (‘lunate ratio’) had a mean of 0.16 (0.11–0.19).

Fractured wrist, PreORIF: Using conventional methods, the mean fracture displacement was 2.64mm (0–5.1mm) and the mean dorsal tilt was 23.3 degrees(4 degrees volar tilt to 43 degrees dorsal tilt). Using the dorsal reference ‘line’, in all cases the lunate was either above or transected by the line; mean lunate ratio of 1.61 (0.54–8.05). The mean height of the lunate projecting dorsal to the line was 9.5mm (6.1–16.1mm).

Fractured wrist, PostORIF: Apart from one radiograph, the ‘line’ passed superior to the lunate; mean distance of 2.64mm (0–3.9mm), with a mean lunate ratio of 1.13 (0.61–2.74). These measurements correlated well with measurements of dorsal tilt and displacement.

Discussion: Our study suggests that there is a strong relationship between the distal radius and the lunate that could be used to assess fracture displacement and quality of reduction. Its main advantages are simplicity and ease of use despite the presence of metalwork.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 177 - 177
1 Mar 2009
stevenson I Carnegie C Christie E Kumar K Johnstone A
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Aim: To assess the ability of volar locking plates to maintain fracture reduction when used to treat dorsally displaced extra and intra-articular distal radial fractures.

Methods: This prospective study was conducted over a 12 month period. Consenting patients who had sustained a closed, dorsally displaced distal radial fracture, treated by open reduction and internal fixation using a volar distal radial locking plate, were included in the study. Radial inclination, volar tilt and ulnar variance were measured from radiographs taken at least 3 months after surgery and compared with radiographs of the uninjured side. Only two of the eight participating surgeons have a specialist interest in upper limb surgery.

Results: Thirty-three patients were included in the study. There were 23 females and 10 males. The mean age was 49.5 years, range 26–82 years. According to the OTA classification there were 19 Type A, 1 Type B and 13 Type C fractures. The mean restoration of volar tilt was 1° of under-correction, median 1.1° under-correction with a range of 7.3° of under-correction to 3.7° of over-correction, when compared with the uninjured side. The mean restoration of radial inclination was 1.9° of under-correction, median 1.6° under-correction with a range of 10° of under-correction to 8.4° of over-correction. As a group the mean ulnar variance was 0mm with a range of 2mm of relative ulnar shortening to 3.5mm of ulnar prominence when compared with the uninjured side.

Conclusion: In the hands of general trauma surgeons, the volar approach combined with the application of a suitable volar locking plate is a good treatment for restoring and maintaining the anatomy of dorsally displaced intra and extra-articular distal radial fractures.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 177 - 178
1 Mar 2009
Tate R Broadbent M Carnegie C Christie E Johnstone A
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Aims: In recent years, volar locking plates have increased in popularity for the treatment of displaced distal radial fractures. The angular stability of the screws help maintain reduction permitting early mobilisation. The aim of this study was to assess functional outcome using both subjective and objective methods.

Methods: The study was a prospective cohort study. Over a 2 year period 110 patients with closed, displaced distal radial fractures were considered suitable for treatment with the distal radius volar locking plate. Of these, 51 patients were followed up for a full 12 months. One year post-operatively all patients were reviewed and both subjective and objective measurements made:

Subjective:

Pain – visual analogue scale (VAS) (0 = no pain, 10 = worst pain ever).

Overall function – patients’ perception – VAS (0 = no function, 100 = full function).

Objective: Strength – grip and pinch – measured objectively as a percentage of the uninjured side.

Range of Motion – Flexion, extension, pronation and supination – measured objectively as percentages of the uninjured side.

For the purpose of this analysis, the fractures were divided into intra- and extra-articular fracture patterns based on the initial pre-operative X-rays.

Results: The mean age was 55 years (28 – 83), 36 were female and 15 male. Of the fractures, 26 were extra-articular and 25 intra-articular. 28 of the 51 patients had a period of physiotherapy post-operatively. 23 patients were either not referred to physiotherapy or failed to attend.

Subjectively 75% of patients had an excellent result with a pain VAS score of 0–1/10 (mean 0.9 for extra-articular and 1.2 for intra-articular) and an overall function VAS score of 9–10/10 (mean 92% for extra-articular and 86% for intra-articular).

Objective outcome measures were also very good. The results for the extra-articular group showed a mean grip strength of 85%, a mean pinch grip of 91%, a mean flexion of 82%, a mean extension of 88%, a mean pronation of 98% and a mean supination of 98%. The results for intra-articular fractures showed a mean grip strength of 80%, a mean pinch grip of 88%, a mean flexion of 78%, a mean extension of 83%, a mean pronation of 94% and a mean supination of 93%.

Conclusions: Overall patients made an excellent recovery. The majority of patients had little or no pain and almost complete return to function at 12 months post-operatively. Interestingly, individual patient demographics (age, sex, fracture type, physiotherapy) did not make a statistically significant difference to the outcome measures.

This study confirmed excellent functional results comparable with other methods of fixation for extra-articular fractures, but it also showed good results with the more complex intra-articular fractures.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 386 - 386
1 Jul 2008
Stevenson I Johnstone A
Full Access

Restoration of normal anatomy following a distal radial fracture is an important factor in determining functional recovery. However, current methods of assessing dorsal tilt and displacement require ‘true’ lateral radiographs, and important reference points are often obscured by metalwork.

Aims: to investigate if an easily identifiable and predictable relationship exists in the normal wrist between the distal radius and lunate; and if so,to compare fractured wrists (pre and postoperatively)using conventional and new assessment methods.

22 patients with displaced distal radial fractures treated by ORIF, were included. Patients had pre and postoperative radiographs taken of the injured and uninjured wrists. From lateral radiographs, measurements were performed using the PACS system. A line was superimposed upon the dorsal radial cortex 2cm proximal to the wrist passing distally. The following measurements were performed: lunate height, distance from the ‘line’ to the superior and inferior poles of the lunate, and conventional measurements of dorsal tilt and angulation.

Uninjured wrist: Most noticeably the dorsal radial line always passed superior to the lunate, mean distance of 3.27mm (1.75-6.6mm). As a ratio, the distance from the line to the superior pole of the lunate divided by the distance to the inferior pole (‘lunate ratio’) had a mean of 0.16 (0.11-0.19).

Fractured wrist, PreORIF: Using conventional methods, the mean fracture displacement was 2.64mm (0-5.1mm) and the mean dorsal tilt was 23.3 degrees(4 degrees volar tilt to 43 degrees dorsal tilt). Using the dorsal reference ‘line’, in all cases the lunate was either above or transected by the line; mean lunate ratio of 1.61 (0.54-8.05). The mean height of the lunate projecting dorsal to the line was 9.5mm (6.1-16.1mm).

Fractured wrist, PostORIF: Apart from one radiograph, the ‘line’ passed superior to the lunate; mean distance of 2.64mm (0-3.9mm), with a mean lunate ratio of 1.13 (0.61-2.74). These measurements correlated well with measurements of dorsal tilt and displacement.

Our study suggests that there is a strong relationship between the distal radius and the lunate that could be used to assess fracture displacement and quality of reduction. Its main advantages are simplicity and ease of use despite the presence of metalwork.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 374 - 375
1 Jul 2008
Karuppiah S Shepherd D McConnachie J Johnstone A
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Introduction: For years traditional intramedullary nails (IMNs) have been used with great success to treat long bone fractures, however, based upon our clinical observations, we hypothesise that design changes incorporated into newer femoral IMNs reduces fracture stability resulting is a higher incidence of non-union.

AIMS: To biomechanically test the factors that may reduce fracture stability.

Materials and methods: The fracture fixation model consisted of custom made stainless steel IMNs of different wall thicknesses and outer diameters, cylinders manufactured from stainless steel, aluminium or HDPE of differing inner diameters and wall thicknesses, and 5mm rods made from stainless steel or titanium. The dimensions of the cylinders were chosen to resemble those commonly observed in the distal femur. The test nails and cylinders were connected using a single rod. Axial loading was undertaken up to 2KN (constant rate of 0.5KN/sec) and repeated a minimum of three times. The effects of various factors such as IM nail wall thickness and outer diameter, the alloy from which the rods were manufactured, and, the diameter, wall thickness and material properties of the cylinders were studied.

Results: The factors that most affected stability were the diameter, wall thickness and the material properties of the cylinders, with the least stable configuration being a HDPE cylinder with a diameter of 75mm and a wall thickness of 3mm. By reducing the diameter of the cylinder to 50mm combined with increasing the wall thickness to 5mm, stability increased considerably even when HDPE was used. The stability of each fracture fixation system was further reduced by using titanium rods.

Discussion: In clinical practice, new femoral IMNs permit longer cross screws to be inserted in the distal femur where the diameter is greatest and the cortical bone is thinnest. Since cancellous bone offers little resistance, screws effectively span from one cortex to the other gaining limited purchase in the bone. As a result, the newer IMN systems are more likely to displace regardless of the direction and force applied. This effect is exaggerated by using titanium. Overall the combination of screw length, choice of alloy and cortical thickness could easily explain our unsatisfactory clinical observations.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 394 - 394
1 Oct 2006
Hamilton S Johnstone A Bradley R
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Introduction: The knee meniscus is prone to injury and has limited intrinsic healing potential despite surgical repair. Methods to enhance fibrochondrocyte function and augment meniscal repair would be invaluable in the treatment of meniscal injuries. Ultraviolet Ozone (UVO) modified surfaces have been characterised chemically and topographically. These surfaces have been shown to promote the function of certain cell types. This study investigated the attachment, proliferation and extracellular matrix production of fibrochondrocytes cultured on UVO modified polystyrene surfaces. Interest was paid to the integrins, a group of transmembrane extracellular matrix attachment glycoproteins. In particular the subunits alpha2 and alpha5, as they specifically bind to the ligands Collagen Type I and Fibronectin, major components in the human meniscus.

Methods: Tissue samples from adult human medial meniscal tears were obtained at knee arthroscopy. Fibrochondrocytes were isolated by standard cell culture techniques and cultured to 100% confluence before seeding onto UVO modified polystyrene surfaces. The untreated polystyrene surfaces of culture dishes were oxidatively modified with an ultraviolet ozone treater. The response of fibrochondrocytes to various surface oxygen concentrations was investigated. Untreated, hydrophobic surfaces acted as controls. Images of cells in culture were obtained with a Leica digital camera mounted on a microscope. Cells were counted at 24, 48, 72 and 96 hours. After 48 and 96 hours of culture standard wet transfer Western Blots were undertaken using antibodies to the alpha2 and aalpha5 integrin subunits (Santa Cruz Biotechnology). To evaluate potential extracellular matrix production total protein assays were undertaken at 1, 2, 3, 4, 6, 8 and 10 days of culture (Bio-Rad Laboratories).

Results: Fibrochondrocytes attached preferentially to the UVO treated surfaces. They proliferated steadily until they reached confluence at 96 hours. Western Blot analysis showed the integrin subunit a5 to be present in the cell lysate after both 48 and 96 hours of culture. The a2 subunit was not detected at these times. There was no increase in total protein concentration on surfaces after fibrochondrocytes had reached confluence. Discussion: UVO modified surfaces promote the attachment and proliferation of human fibrochondrocytes. The alpha2 subunit was not detected in the cell lysate of these surfaces after culture for 96 hours. Whether this is due to defective or absent Collagen Type I at this stage of culture remains to be answered. The presence of the alpha5 subunit suggests that Fibronectin may be involved in the process of fibrochondrocyte attachment to UVO modified polystyrene surfaces. It is suggested that there is little or no extracellular matrix production after 4 days as there is no increase in total surface protein concentration after confluence is reached. The increase in total surface protein concentration up to this point most likely reflects cell proliferation.

Conclusion: Ultraviolet Ozone modified surfaces enhance certain aspects of fibrochondrocyte function and therefore have a potential role in the development of novel therapies for meniscal repair.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 136 - 136
1 Mar 2006
Shakeel M Johnstone A
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Background: There is a huge controversy regarding the period of immobilization after Bankart stabilisation. This ranges from 2 days to 5 weeks for open repair and from 3 to 6 weeks for arthroscopic Bankart repair. We believe it is inappropriate to immobilise the operated shoulder after Bankart repair. In our study all the patients were allowed to use their arm, the same day, pain permitting. No restrictions were imposed for the type and range of movement for those who had open repair. With arthroscopic repair they were asked to limit their shoulder abduction upto 45-degreee and external rotation to neutral.

Method: In this retrospective study (1998–2003) we have analyzed the outcome of mobilisation of operated shoulder on the same day.43 primary stabilisations were performed by the senior author.one patient was uncontactble. We reviewed the records of 42 patients. Subsequently the General Practitioners were contacted to collect information about these patients and the patients were contacted, if needed. Out of 42 patients 34 were males and 8 females. 35 patients had an average of 7 episodes of anterior shoulder dislocations (range 2–25), 7 had unstable shoulder pre-operatively.30 had open repair, 12 had arthroscopic stabilisation. The average follow-up is 3.5years(1–6 years).

Result: 41 patients did hot have any further episode of frank anterior shoulder dislocation and they had returned to their previous level of activities. Only one patient injured his operated shoulder year later while playing football. He underwent arthroscopic capsular shrinkage for traumatic deformation of the capsular and inferior glenohumeral ligament.

Conclusion: In primary straightforward Bankart stabilisation, same day mobilisation does not increase the risk of anterior shoulder dislocation


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 308 - 308
1 Sep 2005
Elliott K Johnstone A
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Introduction and Aims: To assess the effects of the various stages of intra-medullary (IM) nailing of the tibia upon intra-compartmental pressure (ICP) measurements, with particular emphasis on factors which reduce the pressure.

Method: Using sensitive transducer-tipped pressure monitors, the anterior compartment pressure was recorded throughout IM nailing of tibial shaft fractures in 34 consenting patients.

Results: Significant peaks in ICP, up to 140mmHg, occurred during reaming and nail insertion, with a sustained elevated pressure phase seen following nail insertion (p< 0.01). In those patients with no fracture distraction visible on fluoroscopy following nail insertion, this pressure was relieved by the release of traction (mean reduction 16.79mmHg, p< 0.01). However, in those with a visible fracture gap, traction release was not sufficient, and impaction of the fracture after distal cross-screw insertion was required to achieve baseline levels in this group (mean reduction 15.29mmHg; p< 0.01).

Conclusions: Using the various pressure criteria for diagnosing ACS, some of our patients either had, or were at considerable risk of developing ACS post-operatively. Furthermore, if fracture impaction had not been performed where necessary, the subsequent sustained increase in ICP would have resulted in additional patients fulfilling the diagnostic criteria for ACS. Clearly, this observation may explain the tendency for some distracted fractures to fail to unite as a result of ischaemia, but of greater significance is the potential for ACS to occur in the post-operative period, leading to significant long-term complications. We recommend that, if traction is used, it is released as early as possible following nail insertion, and that the fracture should be impacted following distal cross-screw insertion if there is visible distraction of the bone ends on fluoroscopy following nail insertion.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 346 - 346
1 Sep 2005
Tumia N Johnstone A
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Introduction and Aims: There has been a lack of studies investigating the effect of cytokines on human meniscal cartilage. We investigated the regenerative potential of meniscal cartilage at different zones of human and sheep menisci under the effect of platelet-derived growth factor AB (PDGF-AB), insulin-like growth factor I (IGF-I), and basic fibroblast growth factor (bFGF) in a dose-dependent manner.

Method: Monolayer cell cultures were prepared from the inner (avascular), middle, and outer (vascular) zones of human and sheep lateral menisci. Fibrochondrocytes were exposed to various concentrations of each of the three growth factors. To assess cell proliferation, 3H-Thymidine uptake assay was used. For assessment of matrix formation, radioactive 35S uptake assay and Blyscan assay were used to assess newly formed glycosaminoglycans (GAGs), 14C-Proline uptake assay and ELISA were used to assess newly formed collagen.

Results: The growth factors under investigation stimulated the fibrochondrocytes isolated from all meniscal zones in a similar dose-dependent fashion. In human meniscal cells, PDGF-AB at a concentration of 200 ng/ml stimulated proliferation by up to four-fold and GAGs synthesis by up to 12-fold (p < 0.001). IGF-I and to a lesser extent bFGF, at concentrations of 100 and 200 ng/ml, also stimulated both cell proliferation and matrix formation in all three meniscal zones (p < 0.001). PDGF and to a lesser degree IGF at concentrations of 100 and 200 ng/ml have stimulated collagen type I synthesis by up to two-fold.

Conclusion: The results of this study indicate that fibro-chondrocytes originating from the avascular zone of the meniscus have the ability to proliferate and to regenerate their surrounding extracellular matrix when exposed to growth factors. This is an encouraging observation that will form the basis for in vivo research, aimed at enhancing meniscal repair, even within the avascular zone, following surgical repair.


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_III | Pages 375 - 375
1 Mar 2004
Elliott K Johnstone A
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Aims: To assess the effects of the various stages of intramedullary (IM) nailing of the tibia upon intracompartmental pressure (ICP) measurements, including new factors such as fracture impaction. Methods: Anterior compartment pressure monitoring was performed on 25 consenting patients undergoing IM nailing for tibial shaft fractures, using a sensitive transducer-tipped pressure monitor. Results: Signiþcant peaks in ICP, up to 130mmHg, occurred during reaming and nail insertion. Although the ICPs recorded post-operatively (32.79mmHg; range 10 to 68mmHg) were higher than the initial recordings (25.83mmHg; range 8 to 61mmHg), the change was not statistically signiþcant. Reduction of ICP was achieved through release of the traction, but the greatest drop in ICP followed impaction of the fracture after distal cross screw insertion (mean drop 21.75mmHg; range 5 to 58mmHg; p< 0.01). Conclusions: Using the various criteria for diagnosing acute compartment syndrome (ACS), some of our patients either had, or were at considerable risk of developing ACS postoperatively. Furthermore, if fracture impaction had not been performed where necessary, the subsequent sustained increase in ICP would have resulted in additional patients fulþlling the diagnostic criteria for ACS. Clearly, this observation may explain the tendency for some distracted fractures to fail to unite as a result of ischaemia, but of greater signiþcance is the potential for ACS to occur in the postoperative period, leading to signiþcant long term complications.


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_III | Pages 344 - 344
1 Mar 2004
Tumia N Johnstone A
Full Access

Aims: This study investigated the regenerative potential of different parts of human and sheep menisci when exposed to PDGF-AB, IGF-I, and bFGF in a dose dependent manner. Methods: Monolayer cell cultures were prepared from inner, middle, and outer zones of the lateral menisci of sheep and from humans obtained following total knee replacement and partial meniscectomy. Various concentrations of each of the three growth factors were used in addition to control samples. Wemeasured the incorporation of Radio-labelled thymidine to assess cell proliferation and radioactive sulphate and radio-labelled proline to assess matrix formation. Results: Both PDGF-AB and IGF-I have a signiþcant effect in promoting both þbrochondrocyte proliferation and matrix formation in the all meniscal zone zones at 100 and 200 ng/ml (p< 0.001). However, cells isolated from the inner avascu-lar zone of the meniscus showed a higher response than those isolated from the outer vascular zone. bFGF has also stimulated both cell proliferation and matrix formation, but to a lower degree in comparison to PDGF-AB and bFGF, in all meniscal zones of sheep meniscus (p< 0.05). Whereas, in humans, bFGF stimulated only cell isolated form the inner zone of the meniscus (p< 0.05). Conclusions: These results indicate that the meniscal tissue in the avascular zone has the ability to regenerate when exposed to growth factors such as PDGF, IGF-I, and bFGF. This could improve the therapeutic methods to treat meniscal injuries and, ultimately, reduce the incidence of osteoarthritis of the knee.


The Journal of Bone & Joint Surgery British Volume
Vol. 76-B, Issue 5 | Pages 688 - 689
1 Sep 1994
Johnstone A Beggs I


The Journal of Bone & Joint Surgery British Volume
Vol. 74-B, Issue 3 | Pages 400 - 402
1 May 1992
Bell K Johnstone A Court-Brown C Hughes S

We discuss the role of primary knee arthroplasty in supracondylar and intercondylar fractures of the femur in elderly patients with reference to 13 cases. This method of treatment is shown to be effective and to have good results. It is recommended for all type C and some type A supracondylar fractures in old people.