Andy Khye Soon Yew

Surgically treated cervical myelopathy: a functional outcome comparison study between multilevel anterior cervical decompression fusion with instrumentation and posterior laminoplasty

BACKGROUND CONTEXT Multilevel cervical myelopathy can be treated with anterior cervical discectomy and fusion (ACDF) or corpectomy via the anterior approach and laminoplasty via the posterior approach. Till date, there is no proven superior approach. PURPOSE To elucidate any potential advantage of one approach over the other with regard to clinical midterm outcomes in this study. STUDY DESIGN A prospective, 2-year follow-up of patients with cervical myelopathy treated with multilevel anterior cervical decompression fusion and plating and posterior laminoplasty. PATIENT SAMPLE In total, 116 patients were studied. Sixty-four patients underwent ACDF two levels and above or anterior cervical corpectomy and fusion one level and above. Fifty-two patients underwent posterior cervical surgery (laminoplasty C3-C6 and C3-C7). OUTCOME MEASURES Self-report measures: Japan Orthopedic Association (JOA) score, JOA recovery rate, visual analog scale for neck pain (VASNP), neck disability index (NDI), and American Academy of Orthopaedic Surgeons (AAOS) neurogenic symptom score (AAOS-NSS). Physiologic measures: range of motion (ROM) flexion and extension of neck. Functional measures: short-form 36 (SF-36) score comprising physical functioning, physical role function, bodily pain, general health, vitality, social role function, emotional role function, and mental health scales. METHODS Comparison of the JOA scores, JOA recovery rates, NDI scores, SF-36 scores, VASNP, and ROM preoperatively to 2 years. Chi-square and two-sided Student t tests were used to analyze the variables. RESULTS Posterior surgery took an hour shorter (p<.05) and had better improvement in JOA scores at early follow-up of 6 months (p=.025). Anterior surgery group had better improvement of NDI scores at early follow-up of 6 months (p=.024) and was associated with less blood loss intraoperatively compared with posterior surgery. There was no statistical difference between the two groups for JOA scores, JOA recovery rates, SF-36 quality-of-life scores, NDI, AAOS-NSS, VAS neck pain, and ROM at 2 years. Complications were higher for anterior surgery group: two hematoma postoperation, one vocal cord paresis, and one new onset C6/C7 dermatome numbness versus one dura leak in posterior surgery group. CONCLUSIONS Our study showed that patients with multilevel disease treated with laminoplasty do well and compare favorably with patients treated with an anterior approach. Notably, posterior surgery was associated with shorter operating time, better improvement in JOA scores at 6 months, and a tendency toward lesser complications. Posterior surgery was not associated with increased neck disability and neck pain at 2 years. Anterior surgery had better NDI improvement at early follow-up. There is a need for a larger study that is prospectively randomized with long-term follow-up before we can confidently advocate one approach over the other in the management of cervical myelopathy.

Effect of Obesity on Outcome of Hallux Valgus Surgery

Background: Obesity is a global epidemic, but its effect on foot and ankle surgeries is not well defined. This study aimed to investigate the influence of obesity on functional outcome scores, incidence of postoperative surgical site infection (SSI), and repeat surgery after hallux valgus (HV) corrective surgery. Methods: Between January 2007 and December 2011, 452 patients who underwent HV corrective surgery at a tertiary hospital were evaluated. They were categorized into 2 groups based on their body mass index (BMI): (1) BMI less than 30 kg/m2 (control); (2) BMI 30 kg/m2 or more (obese). The patients were prospectively followed for 2 years. Results: Patients in the obese group were significantly older by 4 years (95% CI, 1-7 years) (P = .043). The preoperative American Orthopaedic Foot & Ankle Society Hallux Metatarsophalangeal-Interphalangeal (AOFAS Hallux MTP-IP) Scale and Physical Component Score were 6 points (95% CI, 1-11 points) and 3 points (95% CI, 1-6 points) poorer, respectively, in the obese group (P = .014 and P = .032, respectively). However, the Visual Analog Scale, AOFAS Hallux MTP-IP Scale, Physical Component Score, and Mental Component Score were comparable between the 2 groups at 6 months and 2 years of follow-up (all P > .05). Eleven patients (3%) in the control group and 1 patient in the obese group (2%) developed postoperative SSI (P = .777). Nine patients (2%) in the control group and 7 patients in the obese group (14%) required repeat surgery for complications (P < .001). Conclusion: The authors conclude that while it is important to warn obese patients of the significantly higher risk of repeat surgery, these patients should not be excluded from undergoing HV surgery. Level of Evidence: Level III, retrospective comparative series.

Prospective randomised trial comparing unlinked, modular bicompartmental knee arthroplasty and total knee arthroplasty: A five years follow-up

BACKGROUND A significant proportion of patients with knee osteoarthritis have articular degeneration that is limited to the medial and patellofemoral compartments. The objective of this study was to compare clinical outcomes of unlinked bicompartmental knee arthroplasty (BCA) and total knee arthroplasty (TKA) at 5years in this subset of patients. METHODS 48 patients were randomised into two groups: unlinked, modular bicompartmental arthroplasty and total knee arthroplasty. Data on demographics and clinical outcomes were collected (Bartlett Knee Score, Oxford Knee Score, Knee Society Score). Data on intra-operative blood loss in both groups were also recorded. RESULTS Out of the 48 patients, 26 underwent BCA and 22 had TKA. Both groups shared similar demographic profiles. At five years post surgery, there was significant improvement across all functional scores in both groups. However, there was no significant difference in outcome scores in the BCA group compared to the TKA group. The drop in serum haemoglobin levels postoperatively was 1.55 and 2.30g/dl for the BCA and TKA groups respectively (p<.001). The total amount of blood loss was 397 and 647ml respectively (p=.001). CONCLUSIONS Unlinked, modular BCA results in similar clinical and functional scores as TKA for medial and patellofemoral arthritis in the mid-term. Intra-operative blood loss was significantly lower in the BCA group compared to the TKA group. BCA is a viable option for a select group of young and active patients with the advantage of reduced intra-operative blood loss and equivalent functional outcomes as TKA.

Comparison of early outcome of Weil osteotomy and distal metatarsal mini-invasive osteotomy for lesser toe metatarsalgia

Purpose To compare the 6-month outcome of Weil osteotomy with distal metatarsal mini-invasive osteotomy (DMMO) in 33 patients with lesser toe metatarsalgia. Methods Records of 33 patients who underwent Weil osteotomy (n=20, 41 toes) or DMMO (n=13, 22 toes) for lesser toe metatarsalgia by a single surgeon were reviewed. 25 of them had a concurrent procedure on the 1st toe. Outcome at 6 months was assessed using the visual analogue score (VAS) for pain, American Orthopaedic Foot and Ankle Society (AOFAS) lesser toe metatarsophalangeal-interphalangeal (MTP-IP) score, and the RAND-36 score. Results The 2 groups were comparable in terms of age, gender, and preoperative MTP joint range of motion (ROM), VAS for pain, AOFAS lesser toe MTP-IP score, and RAND-36 scores. At 6 months, the Weil osteotomy group had a higher RAND-36 (mental) score (92 vs. 78, p=0.026), and the DMMO group had a higher percentage of toes with greater MTP joint ROM (p=0.043). All patients achieved bone union within 6 months. Two patients in the DMMO group had prolonged oedema until 3 months post-surgery. Conclusion DMMO is a safe and reliable alternative to Weil osteotomy for metatarsalgia and can preserve ROM of the MTP joints.

Association of surgeon factors with outcome scores after total knee arthroplasty

Purpose. To identify preoperative factors (including surgeon factors) associated with outcome scores after total knee arthroplasty (TKA). Methods. Medical records of 2848 patients (3458 knees) who underwent primary TKA by 27 orthopaedic specialists were retrieved. Three specialty knee surgeons who had one-year fellowship in TKA performed 1930 TKAs, and 24 general orthopaedic surgeons performed 1528 TKAs. Four of them (including all 3 specialty knee surgeons) were ultra-high-volume (⩾100 TKAs a year), and 21 of them were senior consultants (⩾5 years post residency). At 2 years, 2922 (85%) of knees had complete follow-up data. Oxford Knee Score, Knee Society knee and function scores, and SF-36 quality-of-life score were assessed by independent physiotherapists before and after surgery. Outcomes were compared in terms of dichotomised specialty, seniority, and surgical volume of surgeons. Results. Comparing ultra-high-volume (⩾100 TKAs per year) specialty knee surgeons with general orthopaedic surgeons, the former achieved better outcomes in terms of the Oxford Knee Score at 6 months, Knee Society knee and function scores at 2 years, and SF-36 scores at 6 months and 2 years. Comparing lower-volume (±100 TKAs per year) specialty knee surgeons with general orthopaedic surgeons, the former still achieved better outcome and quality-of-life scores, except for SF-36 Mental Component Score at 2 years. Conclusion. Specialty training and clinical research in TKA improved outcome and quality-of-life scores.

Intra-articular tranexamic acid wash during bilateral total knee arthroplasty.

Purpose. To compare the outcome after simultaneous bilateral total knee arthroplasty (TKA) with or without an intra-articular tranexamic acid (TXA) wash in terms of blood loss, haemoglobin change, and transfusion requirement. Methods. 35 women and 10 men (mean age, 67.5 years) who underwent primary simultaneous bilateral TKA by a single senior surgeon were compared with 45 matched controls. In the TXA group, 1500 mg of TXA diluted in 100 ml of 0.9% sodium chloride was administered as a wash after cementing of implant and before closure of the retinaculum. At least 5 minutes of contact time was allowed before wound closure and tourniquet deflation. No drain was used. Results. No patients had thromboembolic complication. Compared with controls, the TXA group had lower perioperative blood loss (920 vs. 657 ml, p=0.001), total blood loss (997 vs. 679 ml, p<0.001), blood transfusion rate (60% vs. 37.8%, p=0.035), percentage of patients requiring more than one blood unit (24.4% vs. 8.9%, p=0.048), and length of hospitalisation (6 vs. 4 days, p<0.001). Nonetheless, the 2 groups were comparable in blood units and volume transfused. Conclusion. An intra-articular TXA wash during simultaneous bilateral TXA reduced total blood loss and resulted in a difference of 22.2% in blood transfusion rate and a 2-day reduction in the length of hospital stay.

Evaluation of medial-lateral stability and functional outcome following total knee arthroplasty: results of a single hospital joint registry.

A precept of a successful total knee arthroplasty (TKA) would be a well balanced, stable knee. We analyzed the effects of medial-lateral (ML) stability on functional outcome at 2years post-operatively. Prospectively collected Joint Registry data of all unilateral primary TKAs between 2004 and March 2008 were used. ML stability (Group 1: <5°, Group 2: 6°-9°, Group 3: ≥10°) was assessed by 3 independent researchers. 1500 patients undergoing 1507 arthroplasties were divided into their various groups. Outcome assessment involved range of motion (ROM) and functional outcome, using the Knee Society Function Score (KSS), Oxford Knee Score (OKS) and SF-36 score. At 2years, Group 1 patients reported significantly higher KSS (P<0.001) and SF-36 scores. All groups had good post-operative ROM. A stable knee (ML stability <5°) post TKA is likely associated with significantly better functional outcome.

Prevalence of Metatarsus Adductus in Symptomatic Hallux Valgus and Its Influence on Functional Outcome

Background: Metatarsus adductus (MA) increases the risk of developing symptomatic hallux valgus (HV). This study aimed to determine the prevalence of MA in patients with symptomatic HV and to evaluate how it affected the functional outcome after scarf osteotomy. Methods: Between January 2007 and June 2012, a total of 206 patients who underwent scarf osteotomy for symptomatic HV at a tertiary hospital were included. The metatarsus adductus angle (MAA) was determined using the Modified Sgarlato method, and these patients were categorized into 2 groups: MA (MAA > 20 degrees); and Control (MAA ≤ 20 degrees). The patients were prospectively followed for 2 years. Results: The prevalence of MA was 33% (68/206) with a mean MAA of 24 ± 4 degrees (range = 20-39). There was a 21 ± 12 degrees and 18 ± 9 degrees improvement in hallux valgus angle for the MA and Control groups, respectively (P = .061), whereas there was a 6 ± 4 degrees and 6 ± 3 degrees improvement in intermetartarsal angle for the MA and Control groups, respectively (P = .475). The visual analog scale, AOFAS Hallux Metatarsophalangeal-Interphalangeal Scale, and Physical and Mental Component Scores were comparable between the 2 groups both preoperatively and at 2 years’ follow-up (all P > .05). Two patients in the control group required revision surgery for recurrence symptomatic HV. Conclusion: The authors conclude that MA did not predispose the patient to poorer functional outcome after scarf osteotomy with the advent of good operative techniques. Level of Evidence: Level II, prospective comparative study.

Externalised locking compression plate as an alternative to the unilateral external fixator: a biomechanical comparative study of axial and torsional stiffness

Objectives External fixators are the traditional fixation method of choice for contaminated open fractures. However, patient acceptance is low due to the high profile and therefore physical burden of the constructs. An externalised locking compression plate is a low profile alternative. However, the biomechanical differences have not been assessed. The objective of this study was to evaluate the axial and torsional stiffness of the externalised titanium locking compression plate (ET-LCP), the externalised stainless steel locking compression plate (ESS-LCP) and the unilateral external fixator (UEF). Methods A fracture gap model was created to simulate comminuted mid-shaft tibia fractures using synthetic composite bones. Fifteen constructs were stabilised with ET-LCP, ESS-LCP or UEF (five constructs each). The constructs were loaded under both axial and torsional directions to determine construct stiffness. Results The mean axial stiffness was very similar for UEF (528 N/mm) and ESS-LCP (525 N/mm), while it was slightly lower for ET-LCP (469 N/mm). One-way analysis of variance (ANOVA) testing in all three groups demonstrated no significant difference (F(2,12) = 2.057, p = 0.171). There was a significant difference in mean torsional stiffness between the UEF (0.512 Nm/degree), the ESS-LCP (0.686 Nm/degree) and the ET-LCP (0.639 Nm/degree), as determined by one-way ANOVA (F(2,12) = 6.204, p = 0.014). A Tukey post hoc test revealed that the torsional stiffness of the ESS-LCP was statistically higher than that of the UEF by 0.174 Nm/degree (p = 0.013). No catastrophic failures were observed. Conclusion Using the LCP as an external fixator may provide a viable and attractive alternative to the traditional UEF as its lower profile makes it more acceptable to patients, while not compromising on axial and torsional stiffness. Cite this article: B. F. H. Ang, J. Y. Chen, A. K. S. Yew, S. K. Chua, S. M. Chou, S. L. Chia, J. S. B. Koh, T. S. Howe. Externalised locking compression plate as an alternative to the unilateral external fixator: a biomechanical comparative study of axial and torsional stiffness. Bone Joint Res 2017;6:216–223. DOI: 10.1302/2046-3758.64.2000470.

Drilling the near cortex with elongated figure-of-8 holes to reduce the stiffness of a locking compression plate construct.

Purpose. To compare the stiffness of locking compression plate (LCP) constructs with or without drilling the near cortex with elongated figure-of-8 holes. Methods. 24 synthetic bones were sawn to create a 10-mm gap and were fixed with a 9-hole 4.5-mm narrow LCP. In 12 bones, the near cortex of the adjacent holes to the LCP holes was drilled to create elongated figure-of-8 holes before screw insertion. The stiffness of LCP constructs under axial loading or 4-point bending was assessed by (1) dynamic quasi-physiological testing for fatigue strength, (2) quasi-static testing for stiffness, and (3) testing for absolute strength to failure. Results. None of the 24 constructs had subcatastrophic or catastrophic failure after 10 000 cycles of fatigue loading (p=1.000). The axial stiffness reduced by 16% from 613±62 to 517±44 N/mm (p=0.012) in the case group, whereas the bending stiffness was 16±1 Nm2 in both groups (p=1.000). The maximum axial load to catastrophic failure was 1596±84 N for the control group and 1627±48 N for the case group (p=0.486), whereas the maximum bending moment to catastrophic failure was 79±12 and 80±10 Nm, respectively (p=0.919). Conclusion. Drilling the near cortex with elongated figure-of-8 holes reduces the axial stiffness of the LCP construct, without compromising its bending stiffness or strength.