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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 10 - 10
16 May 2024
McMenemy L Nguyen A Ramasamy A Walsh M Calder J
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Autologous osteochondral transplantation (AOT) is an effective treatment for large Osteochondral Lesions of the Talus (OLT), however little is reported on an athletic population, who are likely to place higher demands on the reconstruction. The aim is to report the outcomes of large OLT (>150mm2) within an athletic population. The study population was limited to professional or amateur athletes (Tegner score >6) with an OLT of size 150mm2 or greater. The surgical intervention was AOT with a donor site from the lateral femoral condyle. Clinical outcomes at a minimum of 24 months included Return to Sport, VAS and FAOS Scores. In addition, graft incorporation was evaluated by MRI using MOCART scores at 12 months post-surgery. 38 athletes including 11 professional athletes were assessed. Mean follow-up was 46 months. Mean lesion size was 249mm2. 33 patients returned to sport at their previous level and one did not return to sport (mean return to play 8.2 months). Visual analogue scores improved from 4.53 pre-operatively to 0.63 post-operatively (p=0.002). FAOS Scores improved significantly in all domains (p< 0.001). Two patients developed knee donor site pain, and both had three osteochondral plugs harvested. Univariant analysis demonstrated no association between pre-operative patient or lesion characteristics and ability to return to sport. However, there was a strong correlation between MOCART scores and ability to return to sport (AUC=0.89). Our study suggests that AOT is a viable option in the management of large osteochondral talar defects in an athletic population, with favourable return to sport levels, patient satisfaction, and FAOS/VAS scores. The ability to return to sport is predicated upon good graft incorporation and further research is required to optimise this technique. Our data also suggests that patients should be aware of the increased risk of developing knee donor site pain when three osteochondral plugs are harvested.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_3 | Pages 46 - 46
23 Feb 2023
Morris H Cameron C Vanderboor T Nguyen A Londahl M Chong Y Navarre P
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Fractures of the neck of femur are common in the older adult with significant morbidity and mortality rates. This patient cohort is associated with frailty and multiple complex medical and social needs requiring a multidisciplinary team to provide optimal care. The aim of this study was to assess the outcomes at 5 years following implementation of a collaborative service between the Orthopaedic and Geriatric departments of Southland Hospital in 2012.

Retrospective data was collected for patients aged 65 years and older who were admitted with a fragility hip fracture. Data was collated for 2011 (pre-implementation) and 2017 (post-implementation). Demographics and ASA scores were recorded. We assessed 30-day and 1-year mortality, surgical data, length of stay and complications.

There were 74 patient admissions in 2011 and 107 in 2017. Mean age at surgery was 84.2 years in 2011 and 82.6 years in 2017 (p>0.05). Between the 2011 and 2017 groups there has been a non-significant reduction in length of stay on the orthopaedic ward (9.8 days vs 7.5 days, p=0.138) but a significant reduction in length of stay on the rehabilitation ward (19.9 vs 9 days, p<0.001). There was a significant decrease in frequency of patients with a complication (71.6% vs 57%, p=0.045) and a marginal reduction in number of complications (p=0.057). Through logistic regression controlling for age, sex and ASA score, there was a reduction in the odds of having a complication by 12% between 2011 and 2017 (p<0.001). There was no difference in mortality between the groups.

The orthogeriatric model of care at Southland Hospital appears to have reduced both the frequency of complications and length of stay on the rehabilitation ward 5 years after its implementation. This is the first study in New Zealand demonstrating medium-term post-implementation follow-up of what is currently a nationally accepted standard model of care.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 72 - 72
1 Dec 2022
Lamer S Ma Z Mazy D Chung-Tze-Cheong C Nguyen A Li J Nault M
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Meniscal tears are the most common knee injuries, occurring in acute ruptures or in chronic degenerative conditions. Meniscectomy and meniscal repair are two surgical treatment options. Meniscectomy is easier, faster, and the patient can return to their normal activities earlier. However, this procedure has long-term consequences in the development of degenerative changes in the knee, potentially leading to knee replacement. On the other hand, meniscal repair can offer prolonged benefits to the patients, but it is difficult to perform and requires longer rehabilitation.

Sutures are used for meniscal repairs, but they have limitations. They induce tissue damage when passing through the meniscus. Furthermore, under dynamic loading of the knee, they can cause tissue shearing and potentially lead to meniscal repair failure.

Our team has developed a new technology of resistant adhesive hydrogels to coat the suture used to repair meniscal tissue.

The objective of this study is to biomechanically compare two suture types on bovine menisci specimens: 1) pristine sutures and 2) gel adhesive puncture sealing (GAPS) sutures, on a repaired radial tear under cyclic tensile testing.

Five bovine knees were dissected to retrieve the menisci. On the 10 menisci, a complete radial tear was performed. They were separated in two groups and repaired using either pristine (2-0 Vicryl) or GAPS (2-0 Vicryl coated with adhesive hydrogels) with a single stitch and five knots.

The repaired menisci were clamped on an Instron machine. The specimens were cyclically preconditioned between one and 10 newtons for 10 cycles and then cyclically loaded for 500 cycles between five and 25 newtons at a frequency of 0.16 Hz. The gap formed between the edges of the tear after 500 cycles was then measured using an electronic measurement device. The suture loop before and after testing was also measured to ensure that there was no suture elongation or loosening of the knot.

The groups were compared statistically using Mann-Whitney tests for nonparametric data. The level of significance was set to 0.05.

The mean gap formation of the pristine sutures was 5.61 mm (SD = 2.097) after 500 cycles of tensile testing and 2.38 mm (SD = 0.176) for the GAPS sutures. Comparing both groups, the gap formed with the coated sutures was significantly smaller (p = 0.009) than with pristine sutures. The length of the loop was equal before and after loading. Further investigation of tissue damage indicated that the gap was formed by suture filament cutting into the meniscal tissue.

The long-term objective of this research is to design a meniscal repair toolbox from which the surgeon can adapt his procedure for each meniscal tear. This preliminary experimentation on bovine menisci is promising because the new GAPS sutures seem to keep the edges of the meniscal tear together better than pristine sutures, with hopes of a clinical correlation with enhanced meniscal healing.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 66 - 66
1 Dec 2022
Lamer S Ma Z Mazy D Chung-Tze-Cheong C Nguyen A Li J Nault M
Full Access

Meniscal tears are the most common knee injuries, occurring in acute ruptures or in chronic degenerative conditions. Meniscectomy and meniscal repair are two surgical treatment options. Meniscectomy is easier, faster, and the patient can return to their normal activities earlier. However, this procedure has long-term consequences in the development of degenerative changes in the knee, potentially leading to knee replacement. On the other hand, meniscal repair can offer prolonged benefits to the patients, but it is difficult to perform and requires longer rehabilitation.

Sutures are used for meniscal repairs, but they have limitations. They induce tissue damage when passing through the meniscus. Furthermore, under dynamic loading of the knee, they can cause tissue shearing and potentially lead to meniscal repair failure.

Our team has developed a new technology of resistant adhesive hydrogels to coat the suture used to repair meniscal tissue.

The objective of this study is to biomechanically compare two suture types on bovine menisci specimens: 1) pristine sutures and 2) gel adhesive puncture sealing (GAPS) sutures, on a repaired radial tear under cyclic tensile testing.

Five bovine knees were dissected to retrieve the menisci. On the 10 menisci, a complete radial tear was performed. They were separated in two groups and repaired using either pristine (2-0 Vicryl) or GAPS (2-0 Vicryl coated with adhesive hydrogels) with a single stitch and five knots.

The repaired menisci were clamped on an Instron machine. The specimens were cyclically preconditioned between one and 10 newtons for 10 cycles and then cyclically loaded for 500 cycles between five and 25 newtons at a frequency of 0.16 Hz. The gap formed between the edges of the tear after 500 cycles was then measured using an electronic measurement device. The suture loop before and after testing was also measured to ensure that there was no suture elongation or loosening of the knot.

The groups were compared statistically using Mann-Whitney tests for nonparametric data. The level of significance was set to 0.05.

The mean gap formation of the pristine sutures was 5.61 mm (SD = 2.097) after 500 cycles of tensile testing and 2.38 mm (SD = 0.176) for the GAPS sutures. Comparing both groups, the gap formed with the coated sutures was significantly smaller (p = 0.009) than with pristine sutures. The length of the loop was equal before and after loading. Further investigation of tissue damage indicated that the gap was formed by suture filament cutting into the meniscal tissue.

The long-term objective of this research is to design a meniscal repair toolbox from which the surgeon can adapt his procedure for each meniscal tear. This preliminary experimentation on bovine menisci is promising because the new GAPS sutures seem to keep the edges of the meniscal tear together better than pristine sutures, with hopes of a clinical correlation with enhanced meniscal healing.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 51 - 51
1 Mar 2021
Zhang B Nguyen A Narayan R Huang J
Full Access

Abstract

3D printing of synthetic scaffolds mimicking natural bone chemical composition, structure, and mechanical properties is a promising approach for repairing bone injuries. Direct ink writing (DIW), a type of 3D printing, confers compatibility with a wide range of materials without exposing these materials to extreme heat. Optimizing ink properties such as filament formation capabilities, shear-thinning, and high storage modulus recovery would improve DIW fabrication characteristics. In this study, composite inks based on biodegradable polycaprolactone (PCL), reinforced with nano-hydroxyapatite (HAp), and loaded with vancomycin were designed and evaluated for their rheological properties, wettability, mechanical properties, and antimicrobial properties. The formulated composite inks displayed a shear-thinning behaviour exhibited storage modulus recovery percentages above 80% for all formulations, which is essential for extrusion deposition by DIW at room temperature. Ink formulations were able to form fully interconnected lattice scaffolds with porosities ranging from 42% to 65%. Increasing the HAp concentrations from 55% to 85% w/w increased the shear thinning behaviour and reduced the printed filament width to more closely match the nozzle diameter; this indicates higher HAp proportion reduces ink shrinkage. The scaffold had high wettability at HAp proportions above 65% w/w and the compressive elastic modulus of DIW printed scaffolds exhibited within the range of trabecular bone. Antimicrobial activity was apparent from the agar diffusion assay; zones of inhibition ranging from 15.82 ± 0.25 mm and 20.06 ± 0.25 mm were observed after 24 hr for composite scaffolds loaded with 3% and 9% w/w vancomycin respectively. Vancomycin-loaded PCL/HAp composite inks were developed, displaying good printability, wettability, mechanical properties, and antimicrobial properties, making them an attractive choice for bone repair and regeneration.

Declaration of Interest

(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIII | Pages 145 - 145
1 May 2012
Nguyen A Ling J Gomez B Cabot J Sutherland L Cundy P
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Slipped Capital Femoral Epiphysis (SCFE) is a common paediatric disorder with documented racial predilection. No data exists regarding the Australian indigenous and Australian non-indigenous populations. This study provides a comprehensive demographic and epidemiologic analysis of SCFE in South Australia, with emphasis on establishing associations between increasing obesity and incidence.

A demographic review of all cases of SCFE managed in South Australian public hospitals between 1988 and 2007 was performed. Clinical presentation, surgical management and complication profile information was collected. Given that obesity is implicated in the biomechanical causation of SCFE due to increased shearing forces, particular emphasis was placed on gathering weight, race, gender and age data. A profile of the incidence and nature of SCFE was generated. Comparisons were then drawn between this profile and existing epidemiologic percentile data of weight, age and gender in South Australia.

A rising prevalence of obesity in South Australia corresponded with a rising incidence of SCFE. However, this relationship was not linear as the incidence of SCFE has doubled in the last 20 years and the average weight of SCFE patients has increased markedly.

The indigenous population was found to have higher rates of obesity than the non- indigenous population in South Australia. The indigenous population also has a relative risk of developing a SCFE of over three times the non-indigenous population.

The overall rate of complications in South Australian public hospitals was low, with avascular necrosis being recognised in our profile.

The rise in incidence of SCFE in South Australia; especially noticeable in the indigenous population is associated with an increasing prevalence of obesity. The considerable morbidity associated with SCFE was confirmed in our analysis and further highlights the importance of public health initiatives to tackle obesity in our community.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 32 - 32
1 Jan 2011
Maffulli N Saxena A Nguyen A Li A
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The Achilles tendon is commonly operated on, but has associated wound complications, ranging from 7–14% in previously reported series larger than 100 cases. We report a retrospective review of one surgeon’s practice conducted to assess the prevalence of wound complications associated with acute and chronic rupture repair, peritenolysis, tenodesis, debridement, retrocalcaneal exostectomy/bursectomy, and management of calcific tendinopathy of the Achilles tendon. The study evaluated the incidence of infection, and other wound complications such as suture reactions, scar revision, hematoma, incisional neuromas and granuloma formation.

A total of 219 surgical cases were available for review (140 males, 70 females; average age at the time of surgery: 46.5 ± 12.6 years, range 16–75). Seven patients experienced a wound infection, three had keloid formation, six had suture granulomas, and six had suture abscesses, with an overall complication rate of 22 of 219 surgeries (10.1%). There were no hematomas. Seven patients had additional surgery following their wound complications; some had simple granuloma excision, while one necessitated a flap. Patients with risk factors such as diabetes, smoking and Rheumatoid arthritis necessitating steroids were more likely to have a wound complication, (Fisher’s Exact Test, P=.03).

Complications with Achilles tendon surgery may be unavoidable. Suture granulomas may appear in a delayed fashion. Absorbable and non-absorbable suture can be implicated.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 205 - 205
1 Mar 2010
Ling J Gomez B Nguyen A Cabot J Accadbled F Sutherland L Cundy P
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Introduction: Slipped Capital Femoral Epiphysis (SCFE) is the most common hip problem of adolescence. Obesity and African and Pacific Islander races have been associated with increased susceptibility. In the setting of increasing rates of obesity in Australian adolescents over the last twenty years, it is unknown whether the incidence of this condition is increasing. There are no studies to date on the Australian population and it is unknown whether there is an increased incidence in the local Aboriginal population.

Aims: The demographics of SCFE patients presenting to the Women’s and Children’s Hospital (W& CH) in Adelaide were studied, from 1988 to the present, with particular emphasis on weight and race. This was then compared to weight for age percentiles data in the Australian population. The issues of prophylactic pinning of the contralateral side and the efficacy of the department protocol of “pinning in situ” were also studied.

Method: Systematic chart review, statistical analysis, and comparison with data from the Australian Bureau of Statistics and the Centre for Applied Anthropometry, University of South Australia, pertaining to weight and racial mix in South Australia.

Results: SCFE was associated with obesity. Over 45% of the cohort was above the 95th percentile for weight. The mean weight was in the 85th percentile and the median weight was in the 94th percentile.

As an example, the average weight of children aged 12 to 14 years was 13kgs more than the median value of children in this age group.

There was a clear increase in incidence of this condition over the last twenty years which corresponds with increasing obesity rates in the community.

There was a higher incidence in the indigenous population as compared with the non-indigenous population.

Out of the 236 patients enrolled, 5 cases were complicated by avascular necrosis. The overall complication rate was low.

Rate of progression to contralateral slip was low as was the rate of prophylactic pinning.

Conclusions: Our complication rate when compared to other centres is relatively low and would seem to support our consistent protocol of “pinning in situ”. The low rate of progression to contralateral slip also supports our protocol of watchful surveillance rather than mandatory prophylactic pinning of the contralateral side.

We have shown that SCFE is associated with obesity in Australia when compared with general population data. Obesity is also more common in the Aboriginal population and we postulate that this explains the higher incidence of SCFE in this group. In keeping with increasing rates of obesity amongst Australian adolescents, the increasing incidence of this condition further highlights the importance of public health initiatives to tackle obesity in the community.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 210 - 210
1 Mar 2010
Wong* E Nguyen A Sutherland L Cundy P
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Introduction: Studies suggest pedicle screw constructs are more effective than hybrid or hook constructs for AIS correction. This study assessed the efficacy of three methods of spinal instrumentation in patients treated at the WCH.

Methodology: 30 AIS patients who underwent posterior spinal surgery were matched according to age, fusion levels, and Lenke curve. Three constructs were assessed, hook-exclusive, screw-exclusive and hybrid constructs, with 10 patients in each group. Endpoints included radiographic measures, operative time and complications.

Results: Mean pre-operative Cobb angle was 56.1°, 52.2° and 56.7° for the screw, hybrid and hook group respectively.

Structural curve correction was 63.6°, 60.2° and 58.5° for each group respectively. Compensatory curve correction favoured the hybrid and screw groups.

Thoracic kyphosis correction was 20.7° (most improved), 19.9°, and 15.5° for the screw, hook, and hybrid groups respectively.

Coronal alignment favoured the screw construct group.

Comparison of operative time revealed no significant difference, and complication rates were similar in nature and incidence for all three groups.

Conclusions: Results demonstrate improved correction of structural curve, kyphosis, and coronal alignment in the screw instrumentation group. No additional complications were observed with this method of AIS curve correction.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 500 - 500
1 Aug 2008
Maffulli N Saxena A Nguyen# A Li# A Saxena A Alto P
Full Access

Background: The Achilles tendon is commonly operated on, but has associated wound complications, ranging from 7–14% in previously reported series larger than 100 cases.

Methods: A retrospective review of one surgeon’s practice was conducted to assess the prevalence of wound complications associated with acute and chronic rupture repair, peritenolysis, tenodesis, debridement, retrocalcaneal exostectomy/bursectomy, and management of calcific tendinopathy of the Achilles tendon. The study evaluated the incidence of infection, and other wound complications such as suture reactions, scar revision, hematoma, incisional neuromas and granuloma formation.

Results: A total of 219 surgical cases were available for review (140 males, 70 females; average age at the time of surgery: 46.5 ± 12.6 years, range 16–75). Seven patients experienced a wound infection, three had keloid formation, six had suture granulomas, and six had suture abscesses, with an overall complication rate of 22 of 219 surgeries (10.1%). There were no hematomas. Seven patients had additional surgery following their wound complications; some had simple granuloma excision, while one necessitated a flap.

Conclusion: Knowledge of suture materials, proper incision placement and possibly avoiding tourniquet usage can keep complications low when performing Achilles tendon surgery. Regardless, some complications with Achilles tendon surgery may be unavoidable.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_III | Pages 244 - 244
1 Mar 2003
Nyska M Nguyen A Parks B Shabat S Myerson M
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Insertional Achilles tendonitis is an inflammatory disorder affecting mainly active young patients. The etiology is multifactorial and include the combination of anatomical and biomechanical characteristics. One fifth of the tendon injuries in athletes are insertional complaints which includes bursitis and insertion tendinitis.The complex of the insertion of the Achilles tendon includes three main components of fibrocartilage sesamoid, periosteum and enthesis. A conservative regime is recommended as the first line of treatment. In case of failure a surgical decompression of the posterior margin of the calcaneum is indicated.

Nine cadaveric legs were used for the experiment. The leg was mounted on an MTS machine and was axially loaded 360 N. The foot was attached to a plate which enabled dorsal and plantar flexion. The Achilles was sutured twice in an Ethibond No. 5 using the Krakow technique in order to anchor the tendon to an actuator. A thin pressure sensor plate (Teckscan) was inserted into the retrocalcaneal bursa to measure the force, pressure and contact area of the Achilles to the calcaneus in various positions of the foot. The conditions included 90 degrees of the foot, 15 and 30 degrees of dorsiflexion while the tension that was applied on the Achilles was 0, 200 N and 300 N. After resection of the posterior surface of the calcaneus in a 20 degrees inclination.

The mean peak force, pressure and area did not change in Achilles tensioning while the foot was in 90 degrees and were close to zero. In 15 degrees of dorsiflexion there was increase in the mean peak force, pressure and area when the Achilles was tensed to 200 and 300 Newton. Larger increase in these parameters was achieved by further dorsiflexion of the foot to 30 degrees.

After resection of the posterior margin of the calcaneus in an angle of 20 degrees the mean peak force, pressure and area dropped close to zero and remained almost unchanged during the various conditions of the experiment.

Dorsiflexion and tension of the Achilles tendon increases the mean peak force, pressure and area in the Achilles retrocalcaneal bursa. These data may explain the mechanism for insertional Achilles tendinosis. Resection of the posterior surface of the calcaneus in 20 degrees efficiently decompresses the retrocalcaneal bursa in various angles of the foot and in various tensions of the Achilles.