A Longer Duration of Myelopathy Symptoms is Associated With the Lack of Intraoperative Motor Evoked Potential Improvement During Decompressive Cervical Myelopathy Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: We aim to investigate the relationship between the intraoperative motor evoked potential (MEP) signal changes during surgical treatment of cervical myelopathy with postoperative functional outcomes and determine what factors correlate with MEP signal changes. SUMMARY OF BACKGROUND DATA: Intraoperative neurophysiologic monitoring with MEP for cervical cord decompression can potentially predict postoperative neurological complications. MATERIALS AND METHODS: We prospectively collected data from 114 consecutive cervical compressive myelopathy patients who underwent decompressive cervical spine surgery. Functional outcomes were measured preoperatively and postoperatively at the 6-month mark, using the modified Japanese Orthopedic Association score. RESULTS: Among the 114 patients, 87 patients showed significant MEP improvement, 1 patient with MEP degeneration, 3 patients with no change in MEP, and 23 patients with MEP change, but which eventually returned to baseline. Univariate analysis showed that patients with MEP improvement had similar 6-month functional and Japanese Orthopedic Association scores compared with patients who did not have MEP improvement. Critically, a longer duration of symptoms was shown to have a statistically significant relationship with patients who did not have MEP improvement on univariate analysis (49.2 wk in patients with no MEP improvement compared with 34.59 wk in patients with MEP improvement, P = 0.03) but this did not translate to differences in functional outcomes. There was also no statistically significant association between the functional outcome scores and demographics, surgical, or radiologic factors. CONCLUSIONS: Our study shows that the duration of symptoms is not attributed to lower functional outcomes but is associated with a lack of MEP improvement. LEVEL OF EVIDENCE: Level III.

Chemoprophylaxis in addition to mechanical prophylaxis after total knee arthroplasty surgery does not reduce the incidence of venous thromboembolism.

BACKGROUND: Venous thromboembolism (VTE) of the lower limbs is an important complication post total knee arthroplasty (TKA). Current guidelines recommend routine chemical prophylaxis to all patients undergoing this procedure but this is rarely done in Asia as it is believed that Asians have a lower risk of VTE. However, recent evidence suggests otherwise. AIMS: We evaluated the incidence of DVT after TKA in a multi-ethnic Asian population with and without pharmacological prophylaxis, as well as the management and outcome of patients with post-operative DVTs. METHODS: We conducted a retrospective study of consecutive patients who underwent TKA in our hospital from 1st January 2004 to 30th December 2014. All patients were on mechanical thromboprophylaxis via calf pumps after TKA with a postoperative day 3 to 5 doppler ultrasound (DUS) of bilateral lower limbs. 2258 (80.7%) patients did not receive additional chemoprophylaxis, while 540 (19.3%) received chemoprophylaxis on top of mechanical thromboprophylaxis. All patients who received chemoprophylaxis were administered the drug until they were ambulating, with a median administration duration of 6 days. Patients were followed up for a period of 3 months for recurrence of DVTs and 24 months for postoperative outcome scores. RESULTS: Two thousand nine hundred seventy-eight patients had DUS of the lower limbs with 134 diagnosed with DVT giving an incidence of 4.5%. Six of these patients had concurrent PEs. There were 26 (19.4%) proximal DVTs and 108 (80.6%) distal DVTs. After 3 months of follow up, no additional VTE occurred. None of the DVTs or PEs progressed.All DVTs with accompanying PE were proximal. 102 out of 2200 patients (4.6%) without chemoprophylaxis developed DVT as compared to 32 out of 540 patients (5.9%) with chemoprophylaxis, which was not statistically significant (p = 0.13). 19 (0.8%) proximal and 83 (3.8%) distal DVT developed in the patient group without chemoprophylaxis while 4 (0.7%) proximal and 28 (5.2%) distal DVT developed in the patient group with (p = 0.62). Comparison of the incidence of PEs between the two groups, revealed a similar incidence with 5 out of 2200 patients (0.2%) without chemoprophylaxis developing PE as compared to 1 out of 540 patients (0.2%) with chemoprophylaxis (p = 0.87).In addition, patients with chemoprophylaxis showed an association with higher post-operative outcome scores such as post op 6 months SF36 (PCS), post op 12 months SF36 (PCS), post op 12 months SF36 (MCS), post op 24 months SF36 (MCS) and post op 24 months WOMAC. CONCLUSION: In one of the largest Asian studies specifically investigating the incidence of DVT after TKA, we found that the incidence is low at 4.5%. This is in contrast to recent studies that showed higher post-operative VTE rates similar to Western populations. In addition, patients who were administered chemoprophylaxis did not have a statistically significant difference in incidence of VTE although it did show a correlation with higher post-operative outcome scores which may indicate better function. This was seen in functional outcome scores such as post op 6 months SF36 (PCS), post op 12 months SF36 (PCS), post op 12 months SF36 (MCS), post op 24 months SF36 (MCS) and post op 24 months WOMAC.

Effect of Spinal Fusion Surgery on Total Hip Arthroplasty Outcomes: A Matched Comparison Study.

BACKGROUND: Studies regarding postoperative outcomes after primary total hip arthroplasty (THA) in patients who have comorbid factors tend to focus on medical diseases. However, there is a paucity of literature examining the effect of a patient's orthopedic surgical history on outcomes after THA. Significantly, there are currently no studies on the effect of spinal fusion surgery on THA outcomes. METHODS: A review of 82 consecutive patients who had prior spinal fusion surgery who underwent elective THA from January 1, 2006 to December 31, 2015, was conducted. A matching cohort of 82 patients was selected from the remaining THA patients to maintain a 1:1 ratio control group. This cohort of 82 patients was matched for age, gender, body mass index ±5, preoperative Oxford score ±10, total Short Form-36 score ±10, and total Western Ontario and McMaster Universities Arthritis Index (WOMAC) score ±50. Data on the same functional outcomes were prospectively collected at 6-month and 2-year follow-up for comparison. RESULTS: Patients without spinal fusion had better outcome scores than patients with prior spinal fusion, specifically in their 6-month WOMAC scores (253.33-225.07; P = .046), their 2-year Short Form-36 total scores (79.71-69.21; P = .041), and their 2-year WOMAC scores (213.5-267.41; P = .054). CONCLUSION: This study demonstrates that patients with prior spinal fusion had worse outcomes after THA than patients without prior spinal fusion. This has clinical significance in counseling patients with previous spinal fusion undergoing THA.