A systematic review and meta-analysis of hybrid vs. cemented stems - which method is more optimal for revision total knee arthroplasty?

INTRODUCTION: The number of primary and revision Total Knee Arthroplasty (TKA) cases are expected to increase in future. There are various advantages and disadvantage to employing either of the two main types of stem fixation methods - cemented or hybrid technique. This review aimed to study the most optimal fixation method for revision TKAs by comparing radiological outcomes and re-revision rates. METHODS: A systematic review and meta-analysis was performed using PubMed and Cochrane Library from 2010 to identify studies explicitly comparing outcomes between cemented against hybrid fixation revision TKA techniques, with a minimum follow up of at least 24 months. A total of 8 studies was included in this review. Egger's test and visual inspection of the funnel plot did not reveal publication bias. RESULTS: There was no statistically significant difference in radiological failure and loosening (OR 0.79, CI 0.37-1.66, I2 = 29%, p = 0.22), all causes of re-revision (OR 1.03, CI 0.73-1.44, I2 = 0%, p = 0.56) and aseptic revision (OR 0.74, CI 0.27-2.02, I2 = 0%, p = 0.41) between cemented and hybrid techniques. Functional and pain outcomes compared between the two fixation techniques were largely similar across the studies included in this meta-analysis. CONCLUSION: Despite a trend favouring hybrid stems in revision TKA, current evidence revealed that radiological outcomes and re-revision rates are largely similar between cemented and hybrid fixation techniques.

A Modified Surgical Technique of Patellar Tendon Reconstruction in Total Knee Arthroplasty Using Achilles Tendon Allograft.

Patellar tendon disruption is one of the most dreaded complications after total knee arthroplasty (TKA) impacting joint function and implant longevity. Management of this condition remains controversial, and no one treatment has provided consistent clinical success. Here we propose a modified technique from the standard Achilles allograft procedure to reconstruct a ruptured patellar tendon after TKA. A fresh-frozen Achilles tendon allograft with attached calcaneal bone graft was used. Our technique offers the advantage of a more stable graft fixation by relying on both quadriceps tendon and transosseous patellar fixation and bone-to-bone allograft fixation to the tibial tuberosity. The patient regained full extension and discontinued walking aids postoperatively. Careful attention to graft preparation, tensioning, stable graft fixation, and postoperative rehabilitation led to encouraging results in this complex problem.

Isolated Synovial Osteochondromatosis in a Completely Enclosed Suprapatellar Pouch: A Rare Case Report.

INTRODUCTION: A complete suprapatellar plica of the knee is a rare condition that separates the suprapatellar pouch from the rest of the knee cavity. Synovial osteochondromatosis is a rare benign monoarticular arthropathy affecting synovial joints that are clinically manifested as intra-articular multiple loose bodies. Isolated synovial osteochondromatosis within a concealed suprapatellar pouch caused by complete suprapatellar plica is an exceptionally rare occurrence. There is no well-documented report in literature on the diagnosis and arthroscopic approach to osteochondromatosis within a separated suprapatellar pouch. CASE REPORT: We report the case of a 61-year-old man who presented with a 3-month history of atraumatic right knee pain localized to the suprapatellar region. Pre-operative magnetic resonance imaging confirmed the presence of loose bodies at the suprapatellar region behind the complete septum. Loose bodies were concealed in a sealed suprapatellar pouch and could not be detected by routine arthroscopic examination of the knee cavity. The suprapatellar plica was punctured and loose bodies trapped within the enclosed suprapatellar compartment were arthroscopically removed. Histological examination of the loose bodies confirmed the diagnosis of osteochondromatosis. The patient postoperatively experienced complete relief of knee pain. CONCLUSION: Successful arthroscopic removal of loose bodies in the separated suprapatellar compartment requires careful study of pre-operative imaging and can effectively be performed throughthe standard anteromedial and anterolateral arthroscopic portals.

The effect of the comorbidity burden on vitamin D levels in geriatric hip fracture.

BACKGROUND: Elderly patients with hip fractures often have multiple medical comorbidities, and vitamin D deficiency is common in this population. Accumulating evidence links low vitamin D levels to various comorbidities. However, very little is known about the collective impact of comorbidities on vitamin D levels. The Charlson Comorbidity Index (CCI) is a validated comorbidity burden index. We hypothesized that a high CCI score is associated with vitamin D deficiency in elderly patients with hip fracture. METHODS: A retrospective cohort study was conducted among all hospitalized elderly patients aged > 60 years admitted for low-energy hip fracture in a single tertiary hospital from 2013 to 2015. Data regarding patient demographics, fracture type, serum 25-hydroxyvitamin D3 levels and age-adjusted CCI score were collected and analysed. RESULTS: Of the 796 patients included in the study, 70.6% (n = 562) of the patients were women and the mean age was 77.7 ± 8.0 years. The mean vitamin D level was 20.4 ± 7.4 ng/mL, and 91.7% ofhospitalized elderly patients with hip fracture had inadequate vitamin D level. There was no correlation between the individual serum vitamin D level with respect to age-adjusted CCI (Pearson correlation coefficient = 0.01; p = 0.87). After stratifying the CCI scores into low and high comorbidity burden groups (i.e., with scores 1-2 and ≥ 3), there was no relationship between the 2 subgroups for age-adjusted CCI and vitamin D levels (p = 0.497). Furthermore, there was also no association among age, gender, fracture type, and smoking status with the mean 25(OH)D level (p > 0.05). CONCLUSION: Low vitamin D levels were highly prevalent in our hip fracture cohort. There was no relationship between the CCI score and vitamin D levels in the geriatric hip population. The comorbidity burden in geriatric patients with hip fractures did not seem to be a significant factor for vitamin D levels.

A comparison of contiguous two-level anterior cervical discectomy and fusion using a structural allograft versus a Polyetheretherketone (PEEK) cage: the results of a three-year follow-up.

BACKGROUND: Allografts and polyetheretherketone (PEEK) cages are the two most commonly used materials in anterior cervical discectomy and fusion (ACDF). However, their effectiveness in two-level ACDF remains controversial. The primary aim of this retrospective study was to compare the clinical and radiological outcomes of two-level ACDF with plate fixation using either a structural allograft or a PEEK cage. METHODS: From 2010 to 2015, 88 consecutive patients underwent two-level ACDF, of whom 53 received an allograft and 35 patients received a PEEK cage. All PEEK cages were filled with local autografts. All clinical outcomes were prospectively collected before and six months and two years after surgery. Clinical efficacy was evaluated using a visual analogue scale for neck pain and limb pain, the Neck Pain and Disability Score, the Neck Disability Index, the Neurogenic Symptom Score, and the Japanese Orthopedic Association score. Radiological outcomes were assessed preoperatively, immediately after surgery, and at the final follow-up. RESULTS: A preoperative comparison revealed no difference between the two patient groups in terms of age, sex, body mass index, smoking status, preoperative symptoms, operation level, or follow-up (mean = 42.8 months). No differences in the improvements in clinical outcomes were observed between the two groups. Both groups showed significant improvement in mean disc height, segmental height, and segmental lordosis postoperatively. The fusion rate for the PEEK cage was 100% at both levels, while the fusion rate for the allograft group was 98.1% at the cephalad level and 94.2% at the caudad level (p > 0.05). Subsidence at the cephalad level occurred in 22.9% (8/35) of segments in the PEEK group and 7.7% (4/52) of segments in the allograft group (p = 0.057). At the caudal level, a higher incidence of cage subsidence was noted in the PEEK group than in the allograft group [37.1% (13/35) versus 15.4% (8/52)] (p = 0.02). Overall, subsidence was noted in 30% (21/70) of the PEEK group and in 11% (12/104) of the allograft group (p <  0.05). CONCLUSION: The use of PEEK cages resulted in a higher rate of subsidence in two-level ACDF than the use of allografts. Two-level ACDF using either allografts or PEEK cages resulted in similar clinical outcomes, radiological improvements in alignment and fusion rates.

Sub-optimal serum 25-hydroxyvitamin D level affects 2-year survival after hip fracture surgery.

INTRODUCTION: Hypovitaminosis D is a common condition seen in patients with acute hip fracture. We hypothesize that in addition to the other prognosticating factors, hypovitaminosis D may affect survival in patients treated for hip fractures. The objective of this study is to evaluate the impact of serum level of 25-hydroxyvitamin D (25(OH)D) on the survivability after surgical fixation of hip fractures. MATERIALS AND METHODS: We retrospectively studied data collected from January 2013 through December 2015 at a large tertiary hospital in Singapore. Patient's age, gender, Charlson Comorbidity Index (CCI), delay of surgery, fracture patterns, ASA score, as well as their pre-operative serum levels of 25(OH)D, albumin and calcium were examined. Univariate and multivariate logistic regression were used to analyse post-operative outcomes including short (inpatient, 30 and 90 days) and long-term mortality (2 years). RESULTS: Data from 1004 patients were used. Information on the serum level of 25(OH)D was available in 80% of them (n = 801) and more than 90% (n = 735) of the patients had a baseline serum level of less than 30 ng/ml. Mortality rate within this group were 1.1% (n = 9) at 30 days, 1.9% (n = 15) at 90 days and 11.0% (n = 88) at 2 years follow up. Hypovitaminosis D was not a significant risk predictor for short-term mortality, but found to be a significant predictor at 2 years. CONCLUSIONS: In this study, we showed a high prevalence of hypovitaminosis D among the osteoporotic hip fracture population and its impact on 2-year survivorship after hip fracture surgery.

Similar radiological results with accelerometer-based navigation versus conventional technique in total knee arthroplasty.

BACKGROUND: The Zimmer iASSIST system is an accelerometer-based, portable navigation device for total knee arthroplasty (TKA) that does not require the use of a large console for alignment feedback as required in computer-assisted surgery. The purpose of this study was to determine the accuracy of the accelerometer-based system in component positioning and overall mechanical alignment. METHODS: Two groups of 30 patients each with primary osteoarthritis underwent TKA using either conventional method or Zimmer iASSIST navigation in 2013 was retrospectively studied. Patients were matched according to body mass index (BMI), gender and age. A senior arthroplasty surgeon performed all the operation using the same surgical approach. Perioperative and post-operative regimens were the same. All patients had standardized radiographs performed post-operatively to determine the lower limb mechanical alignment and component placement. RESULTS: There was no difference between the two groups for age, BMI, gender, side of operated knee and preoperative mechanical axis ( p > 0.05). There was no difference in the proportion of outliers for mechanical axis ( p = 0.38), coronal femoral angle ( p = 0.50), coronal tibia angle ( p = 0.11), sagittal femoral angle ( p = 0.28) and sagittal tibia angle ( p = 0.33). The duration of surgery, post-operative drop in haemoglobin level and transfusion incidence did not show statistically significant differences between the two groups ( p > 0.05). CONCLUSIONS: Our article showed that iASSIST was safe and remains a useful tool to restore mechanical axis. However, our data demonstrated no difference in lower limb alignment and component placement between the TKA that used accelerometer-based system and those that underwent conventional method.

Intravenous versus intra-articular tranexamic acid in total knee arthroplasty: A double-blinded randomised controlled noninferiority trial.

BACKGROUND: Despite the proven efficacy of both intravenous (IV) and intra-articular (IA) tranexamic acid (TXA) in reducing blood loss during total knee arthroplasty (TKA), the ideal route of administration remained debatable. This study aimed to compare the effect of IV versus IA TXA on transfusion incidences, perioperative blood loss and postoperative lower limb swelling during TKA. METHODS: One hundred patients were prospectively randomised into two groups: 1) IV TXA; and 2) IA TXA. In both groups, TXA was administered intraoperatively after cementing the prostheses. The perioperative blood loss was calculated using the haemoglobin balance method. The thigh, suprapatellar, and calf girths were measured preoperatively and on postoperative day (POD) 4. RESULTS: Two patients in the IV group and one patient in the IA group required blood transfusion (p=0.500). The median and interquartile range (IQR) of perioperative blood loss on POD1 and POD4 was 530 (IQR 386,704) and 730 (IQR 523,925) ml for the IV group, compared with 613 (IQR 506,703) and 799 (IQR 563,1067) ml for the IA group (p=0.090 and p=0.232 respectively). The median increment in thigh, suprapatellar, and calf girths were 1.5 (IQR 0, 3.0), 2.0 (IQR 0.5, 4.0) and 0 (IQR 0, 1.0) cm for the IV group, compared to 2.0 (IQR 1.0, 4.0), 2.0 (IQR 0, 4.5) and 0 (IQR 0, 1.5) cm for the IA group (p=0.246, p=0.562, and p=0.937 respectively). CONCLUSIONS: Both IV and IA TXA had comparable effect on transfusion incidences, perioperative blood loss, and postoperative lower limb swelling during TKA. IA TXA is an alternative to IV TXA. LEVEL OF EVIDENCE: I.

Catheter-related upper limb venous thrombosis in a tertiary hospital setting.

BACKGROUND: To determine the relative likelihood of upper limb venous thrombosis (ULVT) in patients with peripherally inserted central catheter (PICC) versus central venous catheter (CVC), compared with patients without a catheter, in a tertiary hospital setting. METHODS: Retrospective review of all upper limb venous duplex ultrasounds performed for the investigation of venous thrombosis from the Prince of Wales Hospital Vascular Diagnostic Laboratory between July 2009 and October 2012 was conducted. Multivariate logistic regression analysis was used to determine the association between risk factors and the presence of ULVT. The total number of lines inserted was determined from medical, electronic and departmental records. RESULTS: Eight hundred and seventy-six US scans in 637 patients were identified yielding 213 cases of ULVT. ULVT was found in 38/85 scans in patients with PICC, 36/103 scans in patients with CVC and 139/688 scans in patients without a catheter in situ. Compared with patients without catheters, the odds ratio (OR) for developing ULVT was 3.5 (P < 0.001) for PICC and 2.1 (P = 0.002) for CVC. Previous deep venous thrombosis (OR = 11.60; P < 0.001) and malignancy (OR = 2.10; P < 0.02) were additional risk factors. Median time from catheter insertion to diagnosis was 10 days for PICC and 19 days for CVC. The incidence of pulmonary embolism (PE) was 1.8%. The overall 6-month mortality for patients with PICC was 5.9% and CVC was 17.7%. A total of 1855 PICC and 2435 CVC were inserted. The incidence of ULVT was 2.05% per PICC and 1.48% per CVC inserted (P = 0.08). CONCLUSION: Catheters predispose to the formation of ULVT. PICCs are more likely to be associated with ULVT than CVC and have shorter time to symptomatic clot. PE from ULVT is uncommon.

Bilateral femoral neck stress fractures in military recruits with unilateral hip pain.

Femoral neck stress fractures are rare and can be easily missed and failure to diagnose these injuries early can lead to avascular necrosis, malunion and osteoarthritis. It is important to have a high index of suspicion for femoral neck stress fractures in military recruits. We present three cases of bilateral femoral neck fractures in military recruits, all presenting with unilateral hip symptoms and signs. All the asymptomatic contralateral hips had femoral neck stress fractures diagnosed by screening MRI. Tension type and displaced femoral neck fractures were treated surgically. All the fractures managed healing without complications. Military recruits with unilateral groin pain should have an early referral for MRI hip to rule out femoral neck stress fractures and those military personnel with ipsilateral femoral neck fracture should have MRI of the contralateral hip. Two of the patients had vitamin D deficiency, of which one had elevated parathyroid hormones and low bone mineral density. Our case series highlights the significance of vitamin D deficiency among military recruits.

A case report of 3-level degenerative spondylolisthesis with spinal canal stenosis.

INTRODUCTION: Lumbar degenerative spondylolisthesis is a major cause of impaired quality of life and diminished functional capacity in the elderly. Degenerative spondylolisthesis often involves only one or two level and tend to present with one or two level spinal canal stenosis. CASE REPORT: The authors describe an unusual case of degenerative spondylolisthesis involving 3 levels of the lumbar spine from L2 to L5. The patient was a 58-year-old woman who suffered chronic back pain and neurogenic claudication. Plain radiography revealed grade I degenerative spondylolisthesis at L2-L3, L3-L4 and L4-L5. Elevated pedicle-facet joint angles and W-type facet joints at the lumbar spine was observed. Magnetic resonance imaging showed L2-S1 spinal cord compression at the lumbar spine. Patient underwent L2-S1 decompression laminectomy and posterior lateral fusion of L2-S1 with posterior instrumentation and bone grafting. Symptoms improved significantly at 4 months follow-up. CONCLUSION: Thorough evaluation for multilevel segmental involvement in degenerative spondylolisthesis is important because of the frequency of severe symptomatic spinal stenosis or foraminal encroachment. Good surgical outcome can be expected from decompression and stabilisation. The pathogenesis of multi-level lumbar degenerative spondylolisthesis can be complex and heterogeneous.