Elderly Patients Undergoing Minimally Invasive Transforaminal Lumbar Interbody Fusion May Have Similar Clinical Outcomes, Perioperative Complications, and Fusion Rates As Their Younger Counterparts.

BACKGROUND: Although several studies have suggested that minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) may be especially beneficial in the elderly population due to lower operative morbidity and faster postoperative recovery, there are limited studies investigating the functional outcomes, quality of life, and satisfaction in elderly patients after MIS-TLIF. Furthermore, existing studies had substantial clinical, diagnostic, and surgical heterogeneity. QUESTIONS/PURPOSES: We asked if elderly patients could experience comparable (1) patient-reported pain, disability and quality of life, (2) perioperative complications, and (3) radiological fusion rates as their younger counterparts after MIS-TLIF. METHODS: Prospectively collected registry data of patients undergoing primary, single-level, MIS-TLIF for degenerative spondylolisthesis between 2012 and 2014 were reviewed. We included 168 patients, 39 of whom were at least 70 years old. Of the 129 patients younger than 70 years old, propensity-score matching was used to select 39 younger controls with adjustment for sex, BMI, American Society of Anesthesiologists score, and baseline clinical outcomes. Perioperative complications and radiologic data were compared. RESULTS: There was no difference in back pain (mean difference -0.3 [95% confidence interval -1.0 to 0.5]; p = 0.52); leg pain (mean difference -0.1 [95% CI to 0.6-0.5]; p = 0.85); Oswestry Disability Index (mean difference -2.9 [95% CI -8.0 to 2.2]; p = 0.26); and SF-36 physical (mean difference 3.0 [95% CI -0.7 to 6.8]; p = 0.107); and mental component summary (mean difference 1.9 [95% CI -4.5 to 8.2]; p = 0.56); up to 2 years postoperatively; 85% of younger patients and 85% of elderly patients were satisfied (p > 0.99) while 87% and 80%, respectively, had fulfilled expectations (p = 0.36). Four perioperative adverse events occurred in each group. There was also no difference in the rate of fusion (87% in younger patients and 90% in elderly patients; p = 0.135). CONCLUSIONS: When clinical and surgical heterogeneity were minimized, elderly patients undergoing minimally invasive transforaminal lumbar interbody fusion not only had comparable rates of perioperative complications but also experienced similar improvements in pain, function, and quality of life. A high rate of satisfaction was achieved. LEVEL OF EVIDENCE: Level II, prognostic study.

Sagittally Balanced Degenerative Spondylolisthesis Patients With Increased Sacral Slope and Greater Lumbar Lordosis Experience Less Back Pain After Short-Segment Lumbar Fusion Surgery.

STUDY DESIGN: A retrospective review of prospectively collected registry data. OBJECTIVES: (1) Examine functional outcomes of patients with postoperative sacral slope (SS)<30 degrees versus SS≥30 degrees after single-level transforaminal lumbar interbody fusion (TLIF) for degenerative spondylolisthesis (DS); (2) determine the factors associated with SS at the last follow-up. SUMMARY OF BACKGROUND DATA: Few studies have examined the relationship between spinopelvic parameters and functional outcomes in patients with DS undergoing short-segment TLIF. Although SS of 30 degrees has been proposed as the ideal spinopelvic parameter for eliminating residual pain and disability in adult spinal deformity, the ideal value for DS remains unknown. METHODS: Prospectively collected registry data of 63 patients who underwent single-level L4-L5 open TLIF with sagittal realignment for DS were reviewed. Pelvic incidence, lumbar lordosis (LL), pelvic tilt, SS, listhesis excursion, and Bridwell fusion grading were recorded. Patients were stratified into SS<30 degrees (n=26) or SS≥30 degrees (n=37) at the last follow-up. All patients were assessed preoperatively and postoperatively at 2 years. Receiver operating characteristics curve analysis was used to assess the relationship between expectation fulfillment and change in SS. RESULTS: Patients with SS≥30 degrees had significantly lower back pain at 2 years (P<0.04). There were no differences in leg pain or outcome scores (Oswestry Disability Index, Short-Form 36 Physical, and Mental Component Summaries), although there was a trend towards better outcomes and higher satisfaction/expectation fulfillment in patients with SS≥30 degrees. The SS≥30 degrees group had a higher preoperative LL (P=0.04) and SS (P<0.01). Preoperative SS was correlated with SS (R=0.71, P<0.01) and LL (R=0.51, P<0.01) at the last follow-up. The area under the curve for change in SS was 0.680 (95% confidence interval, 0.453-0.907) for predicting expectation fulfillment at 2 years. CONCLUSIONS: Patients with increased SS (≥30 degrees) experienced less back pain after short-segment lumbar fusion surgery. This was associated with increased LL postoperatively, indicating better sagittal balance.

Severity of Preoperative Myelopathy Symptoms Affects Patient-reported Outcomes, Satisfaction, and Return to Work After Anterior Cervical Discectomy and Fusion for Degenerative Cervical Myelopathy.

STUDY DESIGN: Retrospective review of prospectively-collected registry data. OBJECTIVE: To compare the patient-reported outcomes, satisfaction, and return to work among a large cohort of patients stratified by preoperative myelopathy severity undergoing Anterior Cervical Discectomy and Fusion (ACDF) for Degenerative Cervical Myelopathy. SUMMARY OF BACKGROUND DATA: Recent clinical practice guidelines noted a lack of studies stratifying their sample based on preoperative disease severity. The benefits of early surgical intervention for patients with mild myelopathy remain uncertain. METHODS: A prospectively-maintained registry was retrospectively reviewed for all patients who underwent primary ACDF for Degenerative Cervical Myelopathy. Patients were stratified based on severity of preoperative myelopathy symptoms according to the Japanese Orthopaedic Association (JOA) scale: mild (>13), moderate (9-13), or severe (<9). Patients were prospectively followed for at least 2 years. RESULTS: In total, 219 patients were included: 74 mild, 94 moderate, and 51 severe cases. The mild group had significantly better Neurogenic Symptoms (NS), Neck Disability Index (NDI), SF-36 Physical (PCS), and Mental Component Summary at baseline (P < 0.05). Neck and arm pain scores were similar at all time points. At 2 years, the severe group still had significantly worse patient-reported outcomes and lower rates of satisfaction, expectation fulfilment and return to work. However, they had significantly greater improvement in JOA, Neurogenic Symptoms, NDI, PCS, and Mental Component Summary, and a larger proportion attained minimal clinically important difference (MCID) for NDI and PCS. All three groups had similar proportions attaining MCID for JOA. CONCLUSION: Patients with severe myelopathy experienced a greater improvement after ACDF. Although fewer patients attained MCID, early surgical intervention for patients with mild myelopathy should also be considered, as this may allow patients to maintain their higher functional status. They also had high rates of postoperative satisfaction and return to work. The clinical trajectory outlined in this study may provide valuable prognostic information for patients. LEVEL OF EVIDENCE: 3.

Patients With Poor Baseline Mental Health May Experience Significant Improvements in Pain and Disability After Minimally Invasive Transforaminal Lumbar Interbody Fusion: A 5-Year Follow-up Study.

STUDY DESIGN: A retrospective study using prospectively collected registry data. OBJECTIVE: Examine the influence of preoperative mental health on outcomes after Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF). SUMMARY OF BACKGROUND DATA: Prior studies investigating the relationship between mental health and outcomes after lumbar spine surgery included small cohorts with short follow-up and heterogenous fusion techniques. The effect of MIS-TLIF on mental health also remains unclear. METHODS: Prospectively collected registry data of 226 patients who underwent single-level MIS-TLIF at a single institution were reviewed. Patients had completed 5-year follow-up data and were assigned into propensity score-matched groups: poor baseline mental health, that is, low Mental Component Summary (MCS) (<50, n=113) and normal baseline mental health, that is, high MCS (≥50, n=113). Outcomes assessed were visual analog scale for back pain (BP), leg pain (LP), Oswestry Disability Index (ODI), Short-Form 36, North American Spine Society-Neurogenic Symptoms (NS), return to work, return to function, satisfaction, and expectation fulfillment. Length of operation and length of stay were recorded. RESULTS: Preoperative MCS was 40.6±8.2 and 58.5±5.4 in the low and high MCS groups, respectively, after propensity score matching (P<0.001). At 5 years, the high MCS group had significantly lower LP (P=0.020) and NS (P=0.009). Despite a significantly poorer baseline (44.3 vs. 38.7, P=0.007) and 6-month ODI (20.3 vs. 15.7, P=0.018) in the low MCS group, both groups achieved a comparable ODI at 5 years (P=0.084). There was no significant difference in proportion that achieved minimal clinically important difference for ODI, PCS, BP, and LP (P>0.05). Both groups reported similar proportions that return to work. However, the low MCS group had a smaller proportion of patients that return to function at 5 years (P=0.025). CONCLUSIONS: Although patients with poorer baseline mental health had greater pain and worse NS preoperatively and up to 5 years postoperatively, a similar proportion experienced a clinically significant improvement in all outcomes. LEVEL OF EVIDENCE: Level III-nonrandomized cohort study.

Diabetes mellitus does not negatively impact outcomes and satisfaction following unicompartmental knee arthroplasty in well-controlled disease.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) has gained popularity in recent years in view of its minimally invasive nature and proven benefits over the traditional total knee arthroplasty (TKA) in terms of superior knee range of motion and kinametics, faster recovery, lower blood loss, shorter hospital stay and ease of revision with the preservation of bone stock.With the increasing incidence of diabetes mellitus (DM) worldwide and an increased risk of deep infection, wound complications and early failure previously shown in diabetic patients undergoing TKA, it is prudent that we establish the impact of DM on the outcomes and complications of UKA given that there is little on the topic in the current literature.This is especially significant in Asia as Asia is home to more than 60% of the world's population of diabetic patients with estimates of more than 200 million people having the condition. Type 2 DM in particular, is an increasing epidemic with projections to increase by more than 150% between year 2000 and 2035.The purpose of this study is to evaluate the impact of diabetes mellitus on the outcomes and satisfaction of UKA at 2 years postoperatively. We hypothesize that diabetes mellitus does not affect the outcomes and satisfaction following UKA in Asians at 2 years postoperatively. METHODS: We conducted a retrospective review of prospectively collected registry data of 1075 UKAs performed in a multiethnic Asian population between 2006 and 2013 at our institution. Outcomes assessed included flexion range, Knee Society Score (KSS), Oxford Knee Score (OKS), Short-Form 36 (SF-36) and satisfaction scores.All patients with DM were identified and matched with patients without DM for age, gender and body mass index. Outcomes, satisfaction, complication and revision rates were then compared between the two groups up to 2 years postoperatively. Preoperative HbA1c was used to assess the patients' blood glucose control in the DM group. RESULTS: A total of 104 patients (9.7%) had DM, close to the national prevalence (11.3%). At 2 years postoperatively, DM patients had better improvement in their SF-36 Mental Component Score (MCS) (p = 0.015) despite poorer preoperative scores (DM group = 70 ±â€¯23, non-DM group = 77 ±â€¯17, p = 0.013), and were in 1° more varus (p = 0.005) when compared to patients without DM.There was no significant difference in the proportion of patients achieving the minimal clinically important difference for knee-specific outcomes (DM:90%, non-DM:96%) or the satisfaction rates between the groups (DM:92%, non-DM:94%). Complication rates were similar (DM:5.8%, non-DM:4.8%). There were no venous thromboembolic events, deaths or revisions during the follow-up period in both groups. The mean preoperative HbA1c in our DM group was 6.6%. CONCLUSION: In this matched-pair study of diabetic versus non-diabetic patients undergoing surgery for UKA, DM does not have a clinically significant negative impact on the outcomes and satisfaction following UKA in patients with well-controlled disease.

Modern TKA implants are equivalent to traditional TKA implants in functional and patellofemoral joint-related outcomes.

PURPOSE: To compare patient-reported outcomes measures, health-related quality of life and satisfaction rates between a new Modern TKA system (M-TKA) and an existing Traditional TKA system (T-TKA). METHODS: Prospectively collected registry data of 65 patients who underwent T-TKA and 65 patients who underwent M-TKA at a single institution from 2014 to 2015 was reviewed. The range of motion, Knee Society Knee Score (KSKS), Function Score (KSFS), Oxford Knee Score (OKS), SF-36, satisfaction and expectation fulfilment were compared at Pre-op, 6 months and 2 years. Patellofemoral joint-related OKS subscores (3, 5, 7, 12) were also compared between the groups. Minimal clinically important difference (MCID) in OKS/SF-36 were analysed for both groups. Propensity scores generated using logistic regression were used to adjust for confounding variables, thus allowing matching of T-TKA to M-TKA in a 1:1 ratio. RESULTS: Both groups showed a significant improvement in all measured variables at 6 month and 2 years (p < 0.001) when compared to baseline. There was no significant difference in KSKS, KSFS, OKS, SF-36 and Patellofemoral joint-related OKS subscores (3, 5, 7, 12) between the two groups (n.s.). At 2 years, there were high satisfaction rates of 89.2% and 92.2% in the T-TKA and M-TKA groups, respectively (n.s.). Similarly, both groups demonstrated high expectation fulfilment rates of 84.6% and 90.6% for the T-TKA and M-TKA groups, respectively (n.s.). CONCLUSION: Using an extensive battery of standardized patient-reported, health-related quality of life and MCID assessments, our study demonstrated no difference in clinical outcomes between M-TKA and T-TKA that would justify the use of the newer and costlier M-TKA. Longer follow-up is necessary to evaluate the possible advantages of this new implant design. LEVEL OF EVIDENCE: Level III, Retrospective Study.

The effect of gender in hallux valgus surgery. A propensity score matched study.

BACKGROUND: Males and females who undergo hallux valgus (HV) surgery have different expectations. METHODS: Data from 439 patients, with 26 males, were prospectively collected between 2007-2015. Propensity score matching (PSM) of one male to two females was performed using logistic regression of six variables to minimize selection bias. Hallux visual analogue scale (VAS) scores, AOFAS scores, SF-36, satisfaction and expectation scores were analysed at two years. RESULTS: There were no significant differences in patient demographics after PSM. At two years, males and females attained similar VAS and AOFAS scores but males had significantly lower SF-36 general health score (males 68.7, females 79.3). 26.9% of males and 21.2% of females were not satisfied after surgery. Higher proportion of males did not have their expectations fulfilled (males 19.2%, females 5.8%) although this was not statistically significant. CONCLUSIONS: Both genders attain similar outcome at two years. There is a trend towards lower expectation fulfilment in males after surgery.

The Influence of Body Mass Index on Functional Outcomes, Satisfaction, and Return to Work After Single-level Minimally-invasive Transforaminal Lumbar Interbody Fusion: A Five-year Follow-up Study.

STUDY DESIGN: Retrospective study using prospectively collected registry data. OBJECTIVES: To evaluate the effect of obesity on patient-reported outcome measures of pain, disability, quality of life, satisfaction, and return to work after single-level minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). SUMMARY OF BACKGROUND DATA: MIS-TLIF is an appealing alternative for obese patients with potentially lower complication risk. However, there is limited data investigating the influence of obesity on outcomes 5 years after MIS-TLIF. METHODS: Prospectively collected registry data of 296 patients who underwent single-level MIS-TLIF at a single institution were reviewed. Patients had complete 2- and 5-year follow-up data. Patients were stratified into control (<25.0 kg/m), overweight (25.0-29.9 kg/m), and obese (≥30.0 kg/m) groups. Outcomes assessed were visual analogue scale for back pain, leg pain, Oswestry Disability Index, Short-form 36, North American Spine Society score for neurogenic symptoms, return to work (RTW), return to function (RTF), satisfaction, and expectation fulfilment. Length of operation, length of stay, and comorbidities were recorded. RESULTS: Among the patients, 156 (52.7%) had normal weight, 108 (36.5%) were overweight, and 32 (10.8%) were obese. There was no difference in length of operation or hospitalization (P > 0.05). All three groups had comparable preoperative scores at baseline (P > 0.05). At 5 years, the control group had significantly higher PCS compared with the overweight (P = 0.043) and obese groups (P = 0.007), although the change in scores was similar (P > 0.05). The rate of MCID attainment, RTW, RTF, expectation fulfilment, and satisfaction was comparable. CONCLUSION: Nonobese patients had better physical well-being in the mid-term, although obese patients experienced a comparable improvement in clinical scores. Obesity had no impact on patients' ability to RTW or RTF. Equivalent proportions of patients were satisfied and had their expectations fulfilled up to 5 years after MIS-TLIF. LEVEL OF EVIDENCE: 3.

Time Taken to Return to Work Does Not Influence Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion: A 5-Year Follow-Up Study.

STUDY DESIGN: Retrospective cohort study using prospectively collected registry data. OBJECTIVE: To determine factors which influence return-to-work (RTW) in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and to determine if early RTW affects functional outcomes. SUMMARY OF BACKGROUND DATA: MIS-TLIF has been associated with accelerated return to work. RTW in non-WC working-age adults after MIS-TLIF is not well understood. METHODS: Prospectively collected registry data of 907 patients who underwent MIS-TLIF at a single institution from 2004 to 2013 were reviewed. One hundred ten working adults who underwent single-level MIS-TLIF with complete preoperative and 5-year postoperative follow-up data were included. Patients were assigned into Early RTW (≤60 d, n = 40) and Late RTW (>60 d, n = 70). All patients were assessed pre- and postoperatively at 2 and 5 years. Length of operation, length of stay, and comorbidities were also recorded. RESULTS: The Early RTW group had significantly lower Oswestry Disability Index (ODI), North American Spine Society score for neurogenic symptoms (NASS NS), numerical pain rating scale (NPRS) back and leg pain scores than the Late RTW group (<0.01) There were no significant differences in age, body mass index (BMI) and prevalence of medical comorbidities (P > 0.05). In addition, there were no differences in terms of duration of surgery or length of hospitalization. There were no significant differences in ODI, NASS NS, Short-form 36 physical and mental component scores (SF-36 PCS/MCS), NPRS, satisfaction/expectation fulfilment between the Early and Late RTW groups at 2-year and 5-year follow-up. Both groups reported similar proportions that RTW without limitations and return-to-function (RTF) at 2-years and 5-years. CONCLUSION: Patients who RTW late have significantly poorer preoperative SF-36 physical component scores and higher ODI, NASS NS, NPRS back/leg pain scores. Surgeons should be cognizant that working adults with poorer preoperative function will tend to return to work later, but should reassure them that they will likely achieve similar clinical outcomes, satisfaction and expectation fulfilment when compared with patients who returned to work early. LEVEL OF EVIDENCE: 3.

Poor Baseline Mental Health Does Not Influence Improvement in Patient-reported Outcomes, Satisfaction, and Return to Work Two Years After Single-level Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective study using prospectively collected registry data. OBJECTIVE: The authors examine the influence of preoperative mental health on outcomes after anterior cervical discectomy and fusion (ACDF) and determine the impact of ACDF on postoperative mental health. SUMMARY OF BACKGROUND DATA: While studies have reported a negative correlation between preoperative mental health and outcomes following lumbar spine surgery, the influence on outcomes following cervical spine surgery remains relatively understudied. METHODS: Prospectively collected registry data of 104 patients who underwent single-level ACDF for cervical spondylotic myelopathy were reviewed. Patients were dichotomized into top and bottom halves based on preoperative SF-36 MCS (Mental Component Summary) using a cutoff of 48. Outcomes assessed were visual analogue scale for neck pain, arm pain, AAOS Neck Pain and Disability, Neurogenic Symptoms, Neck Disability Index, Short-Form 36, Japanese Orthopaedic Association myelopathy score, return to work, return to function, satisfaction and expectation fulfilment up to 2 years postoperatively. RESULTS: The preoperative MCS was 37.5 ±â€Š8.1 and 57.4 ±â€Š6.3 in the Low and High MCS groups respectively (P < 0.001). The Low MCS group had poorer preoperative scores (P < 0.05). There was no significant difference in length of stay or comorbidities (P > 0.05). The High MCS group had less neck pain (P = 0.002) and showed a trend towards lower Neck Disability Index (P = 0.062) at 2 years. The Low MCS group demonstrated greater improvement in Japanese Orthopaedic Association (P = 0.007) and similar improvement in other scores (P > 0.05). There was no significant difference in proportion that achieved minimal clinically important difference for each score (P > 0.05). Both groups had similar rates of return to work, return to function, expectation fulfilment, and satisfaction (P > 0.05). Lower preoperative MCS was predictive of greater improvement in MCS (r = -0.477, P < 0.001). CONCLUSION: Despite relatively greater pain and disability at 2 years, patients with poor baseline mental health experienced similar improvement in clinical outcomes, return to work, and satisfaction rates. LEVEL OF EVIDENCE: 3.

Patients With Poor Baseline Mental Health Undergoing Unicompartmental Knee Arthroplasty Have Poorer Outcomes.

BACKGROUND: The relationship between mental health and outcomes of unicompartmental knee arthroplasty (UKA) remains unclear. Poor preoperative mental health may be caused by pain and functional limitations associated with knee arthritis. We aimed at (1) investigating the effect of preoperative mental health on early outcomes and (2) assessing whether mental health improves after UKA. METHODS: Prospectively collected registry data of 1473 medial UKAs performed at a single institution in 2007-2014 were reviewed. Linear regression was used to determine improvement in mental health up to 2 years according to preoperative Short-Form 36 Mental Component Summary (MCS). Patients were stratified into low MCS (<50, n = 579) and high MCS (≥50, n = 894). The Knee Society Knee Score (KSKS), Function Score (KSFS), Oxford Knee Score (OKS), Short-Form 36, satisfaction, and expectation fulfilment were compared at 6 months and 2 years. RESULTS: The mean preoperative MCS was 41.2 in low MCS group and 58.6 in high MCS group (P < .001). The high MCS group had higher KSKS, KSFS, OKS, and Physical Component Summary, and a greater proportion of patients were satisfied and had expectations fulfilled at 6 months and 2 years (P < .05). However, the low MCS group demonstrated greater improvement in KSKS, KSFS, and OKS (P < .05). Lower preoperative MCS score was predictive of greater improvement in MCS (coefficient = -0.662, R = -0.602, P < .001). CONCLUSION: Patients with poor mental health benefit from greater improvements in their mental health and knee function after UKA, but also have a greater dissatisfaction.

Body mass index changes after unicompartmental knee arthroplasty do not adversely influence patient outcomes.

PURPOSE: The objective of this study is to evaluate the prevalence of patients who lost or gained weight following unicompartmental knee arthroplasty (UKA), the effect of post-operative body mass index (BMI) changes on functional outcomes and quality of life (QoL), and predictive factors associated with BMI changes. METHODS: Prospectively collected data of 1043 patients who underwent UKA between 2000 and 2014 were reviewed. BMI, Knee Society Knee Score and Function Score, Oxford Knee Score (OKS), Short-Form 36 (SF-36) Physical Component Score (PCS) and Mental Component Score and proportion of patients attaining OKS/SF-36 minimal clinically important differences (MCID) were recorded preoperatively and at 2 years post-operatively. The patients were stratified into three groups based on weight changes for further analysis. RESULTS: Following UKA, 138 (13.3%) patients had lost weight, 695 (66.6%) maintained their weight, and 210 (20.1%) gained weight. Patients in all groups demonstrated significant improvements in functional and SF-36 PCS scores at 2 years post-operatively. There were no significant differences in functional outcomes, QoL or revision rate between the groups. Post-operative BMI changes were not correlated with any outcome scores or attainment of MCID (n.s.). CONCLUSIONS: This is the first study that evaluates change in BMI following UKA. It demonstrated a higher proportion of patients who gained weight as compared to those who lost weight. Post-operative BMI changes did not appear to affect outcomes of UKA. These findings will provide important information to surgeons when counselling patients regarding BMI change and its effect on outcomes after UKA. LEVELS OF EVIDENCE: Level III.

Poorer Fusion Outcomes in Diabetic Cervical Spondylotic Myelopathy Patients Undergoing Single-level Anterior Cervical Discectomy and Fusion Does Not Compromise Functional Outcomes and Quality of Life.

STUDY DESIGN: Retrospective matched pair cohort study using prospectively collected registry data. OBJECTIVES: The aim of this study was to determine whether patients with DM have poorer patient-reported outcomes and poorer fusion rates after undergoing a single-level anterior cervical discectomy and fusion (ACDF) for cervical myelopathy. SUMMARY OF BACKGROUND DATA: ACDF remains the most common procedure in the treatment of cervical spondylotic myelopathy (CSM); however, there is a paucity of literature with regards to patient-reported outcome measures (PROMs), health-related quality-of-life (HRQOL) scores, and fusion rates post-ACDF in diabetic patients with CSM. METHODS: From 2002 to 2012, 29 diabetic patients were matched with 29 nondiabetic controls. Patient demographics, perioperative data, and validated spine-specific scores including the Numerical Pain Rating Scale on Neck Pain and Upper Limb Pain, American Academy of Orthopaedic Surgeons (AAOS) neck pain and disability scores, AAOS Neurogenic Symptoms Score, Neck Disability Index, Japanese Orthopaedic Association Cervical Myelopathy Score, and Short Form 36 Physical/Mental Component Summaries were recorded. Fusion rates based on Bridwell grading were assessed at 2 years. RESULTS: After matching, there were no significant preoperative differences in patient demographics, clinical outcomes, PROMs or HRQoL measures between the DM and control group (P > 0.05). There was no difference in either length of hospital stay (P = 0.92) or length of surgery (P = 0.92) between the two groups. At 2 years postoperatively, there were no significant differences between validated spine-specific scores, PROMs, HRQoL scores, satisfaction rates, or fulfilment of expectations between the two groups. Significant poorer Bridwell fusion grades were noted in the DM group at 2 years postoperatively (P < 0.05). Subgroup analysis within the DM group demonstrated that glycated hemoglobin levels had no impact on functional outcomes, fulfilment of expectations, or patient satisfaction at 2 years (P > 0.05). CONCLUSION: Despite poorer fusion outcomes following single-level ACDF for symptomatic CSM, there was no significant difference in validated spine outcome scores, PROMs, HRQoL measures, or satisfaction levels when compared to nondiabetic controls at short-term follow-up. LEVEL OF EVIDENCE: 3.

Accelerometer-Based and Computer-Assisted Navigation in Total Knee Arthroplasty: A Reduction in Mechanical Axis Outliers Does Not Lead to Improvement in Functional Outcomes or Quality of Life When Compared to Conventional Total Knee Arthroplasty.

BACKGROUND: Accelerometer-based navigation (ABN) is a novel navigation system that attempts to combine the accuracy of computer-assisted surgery (CAS) with the familiarity of conventional instrumentation (CON). No studies have compared the clinical outcomes of this new technology with existing techniques to date. METHODS: From July 2013 to April 2014, 152 consecutive patients (152 knees) underwent total knee arthroplasty using ABN (n = 38), CAS (n = 38), or CON (n = 76). We prospectively matched the groups in a 1:1:2 ratio for age, gender, body mass index, preoperative range of motion, Knee Society Score, Oxford Knee Score, Short-Form 36 Physical and Mental Component Scores, and preoperative deformity using preoperative data in isolation, thus controlling for potential confounding factors. All patients were prospectively followed for 2 years. RESULTS: The ABN and CAS groups had a significantly improved mean mechanical axis (P = .018), femoral (P = .050) and tibial component alignment (P = .008) compared to the CON group. There were significantly less mechanical axis outliers in the ABN and CAS groups (P = .034). The duration of surgery for the ABN group (83.9 ± 21 min) was significantly shorter than the CAS group (101 ± 11 min; P < .001) but similar to the CON group (76.6 ± 17 min; P = .131). There was no significant difference in functional outcomes, quality of life measures or satisfaction rates between the 3 groups at 2 years (P > .05). CONCLUSION: Although bone cuts were as accurate as CAS and operation time was similar to CON, the use of ABN failed to demonstrate any advantages in clinical outcomes following total knee arthroplasty at 2 years follow-up.

Unicompartmental Knee Arthroplasty Achieves Greater Flexion With No Difference in Functional Outcome, Quality of Life, and Satisfaction vs Total Knee Arthroplasty in Patients Younger Than 55 Years. A Propensity Score-Matched Cohort Analysis.

BACKGROUND: Improvements in surgical techniques, implant design, and adherence to indications have resulted in favorable outcomes after unicompartmental knee arthroplasty (UKA), particularly in an older population. However, no studies have compared the performance of contemporary UKA and total knee arthroplasty (TKA) in a young population. METHODS: Prospectively collected registry data of 160 UKAs performed in 160 patients younger than 55 years were reviewed. Propensity scores generated using logistic regression were used to adjust for confounding variables of age, gender, body mass index, preoperative range of motion, Knee Society Score, Oxford Knee Score, and Short-Form 36, allowing matching of the TKA cohort to the UKA cohort in a 1:1 ratio using the nearest-neighbor method. RESULTS: The UKA group had significantly greater flexion at 6 months and 2 years (P < .001). There was no significant difference in Knee Society Score, Oxford Knee Score, and Short-Form 36. At 2 years, 89.4% and 88.8% of the TKA and UKA groups were satisfied (P = 1.00) while 86.9% and 86.3% had their expectations fulfilled (P = 1.00). At a mean follow-up of 7 years, there were 2 revisions in each group (2.2%). CONCLUSION: Although native knee biomechanics are preserved, younger patients do not seem to perceive this oft-cited benefit of UKA, as this did not translate into greater health-related quality of life or patient satisfaction compared to TKA. The theoretical advantages of UKA were not borne out by our findings, other than greater flexion up to 2 years postoperatively.

Robotic-assisted total knee arthroplasty may lead to improvement in quality-of-life measures: a 2-year follow-up of a prospective randomized trial.

PURPOSE: Despite reduction in radiological outliers in previous randomized trials comparing robotic-assisted versus conventional total knee arthroplasty (TKA), no differences in short-term functional outcomes were observed. The aim of this study was to determine whether there was improvement in functional outcomes and quality-of-life (QoL) measures between robotic-assisted and conventional TKA. METHODS: All 60 knees (31 robotic-assisted; 29 conventional) from a previous randomized trial were available for analysis. Differences in range of motion, Knee Society (KSS) knee and function scores, Oxford Knee scores (OKS), SF-36 subscale and summative (physical PCS/mental component scores MCS) were analysed. In addition, patient satisfaction, fulfilment of expectations and the proportion attaining a minimum clinically important difference (MCID) in KSS, OKS and SF-36 were studied. RESULTS: Both robotic-assisted and conventional TKA displayed significant improvements in majority of the functional outcome scores at 2 years. Despite having a higher rate of complications, the robotic-assisted group displayed a trend towards higher scores in SF-36 QoL measures, with significant differences in SF-36 vitality (p = 0.03), role emotional (p = 0.02) and a larger proportion of patients achieving SF-36 vitality MCID (48.4 vs 13.8 %, p = 0.009). No significant differences in KSS, OKS or satisfaction/expectation rates were noted. CONCLUSION: Subtle improvements in patient QoL measures were observed in robotic-assisted TKA when compared to conventional TKA. This finding suggests that QoL measures may be more sensitive and clinically important than surgeon-driven objective scores in detecting subtle functional improvements in robotic-assisted TKA patients. LEVEL OF EVIDENCE: II.

Patient-Reported Outcomes, Quality of Life, and Satisfaction Rates in Young Patients Aged 50 Years or Younger After Total Knee Arthroplasty.

BACKGROUND: Recent studies have shown a discrepancy between traditional functional outcomes and patient satisfaction, with some reporting less than 85% satisfaction in older patients undergoing total knee arthroplasty (TKA). As native knee biomechanics are not completely replicated, the resulting functional limitations may cause dissatisfaction in higher-demand individuals. Few studies have recorded patient-reported outcomes, health-related quality of life scores, and patient satisfaction in a young population undergoing TKA. METHODS: One hundred thirty-six primary TKAs were performed in 114 patients aged 50 years or younger (mean age, 47.0 years; range, 30-50 years) at a single institution. The main diagnoses were osteoarthritis (85%) and rheumatoid arthritis (10%). RESULTS: The range of motion, Knee Society Score, Oxford Knee Score, and Physical and Mental Component Scores of Short Form-36 increased significantly (P < .001). At 2 years, 85.3% of patients had good/excellent knee scores, 71.3% had good/excellent function scores, 94.9% met the minimal clinically important difference for the Oxford Knee Score, and 84.6% met the minimal clinically important difference for the Physical Component Score. We found that 88.8% of patients were satisfied with their surgeries, whereas 86.8% had their expectations fulfilled. Survivorship using revision as an end point was 97.8% at a mean of 7 years (range, 3-16 years). CONCLUSION: Patients aged 50 years or younger undergoing TKA can experience significant improvements in their quality of life, have their expectations met, and be satisfied with their surgeries, at rates similar to those of non-age-restricted populations. Surgeons should inform them of these benefits and the potential risk of revision surgery in the future, albeit increasingly shown to be low.

Intraoperative Measurements of Joint Line Changes Using Computer Navigation Do Not Correlate With Postoperative Radiographic Measurements in Total Knee Arthroplasty.

BACKGROUND: The adverse effects of joint line (JL) changes on kinematics and outcomes of total knee arthroplasty (TKA) have been studied. Some authors have quantified JL changes using intraoperative data from computer navigation, despite no studies validating these measurements to date. We designed a prospective study to determine whether intraoperative measurements of JL changes using computer navigation correlate with measurements obtained on weight-bearing radiographs postoperatively. METHODS: A total of 195 consecutive patients (195 knees) underwent computer-navigated cruciate-retaining TKA by the senior author. Twenty-four patients had missing radiographic data and were excluded from the study. The final JL change was calculated intraoperatively from the verified bony cuts and planned JL change as determined by the computer. JL position was also measured on preoperative and postoperative radiographs using an anteroposterior method. RESULTS: One hundred seventy-one knees were evaluated. Using computer-navigated and radiographic measurements, the mean JL change was 1.95 ± 1.5 mm (0-8.0 mm) and 4.05 ± 2.9 mm (0-17.3 mm), respectively. One hundred fourteen (67%) vs 129 (75%) had JL elevation, 44 (26%) vs 30 (18%) had JL depression, and 13 (7%) vs 12 (7%) had no JL change, respectively. Inter-rater and intrarater reliability of radiographic measurements was excellent. We found a poor correlation between computer-navigated and radiographic measurements (r = 0.303). CONCLUSION: There is a poor correlation between computer-aided and radiographic measurements of JL changes post-TKA. Elevation/depression of the JL needs to be considered in patients who remain symptomatic despite TKA, although the optimal method of assessment remains uncertain.

Computer-assisted stereotaxic navigation improves the accuracy of mechanical alignment and component positioning in total knee arthroplasty.

INTRODUCTION: This study reports on a novel computer-assisted stereotaxic navigation (CASN) system that attempts to combine the accuracy of computer navigation with familiarity of conventional methods. We hypothesize that CASN would improve mechanical alignment and component positioning when compared to conventional instrumentation. MATERIALS AND METHODS: 145 patients (192 knees) retrospectively matched for age, BMI, gender and pre-operative scores, underwent total knee arthroplasty (TKA) using CASN (n = 92) or conventional instrumentation (n = 100). Pre- and post-operative radiological alignment [Acceptable ranges: mechanical axis (MA) 0° ± 3°, coronal femoral-component angle (CFA) and coronal tibia-component angle (CTA) 90° ± 3°] and clinical outcomes (Knee Society Scores, Oxford Knee Score and Short Form-36) at 6 months were examined. RESULTS: The CASN group had significantly improved mean MA (1.9° ± 1.4°, versus 2.8° ± 2.0° in the conventional group, p = 0.001), CFA (1.6° ± 1.3°, versus 2.1° ± 1.5° in the conventional group, p = 0.035) and CTA (1.6° ± 1.2°, versus 2.1° ± 1.5° in the conventional group, p = 0.024). 91.3 % of knees in the CASN group were within 3° of a neutral mechanical axis, versus 74 % in the conventional group (p < 0.001). The duration of surgery was significantly longer in the CASN group (84 ± 22 vs 73 ± 15 min, p = 0.001) and cost an additional USD 850 per operation. There were no significant differences in clinical outcomes or satisfaction rates at 6 months post-operatively (p > 0.05). CONCLUSIONS: CASN improved TKA mechanical alignment and component positioning, however, resulted in longer and costlier surgery with no benefits in short-term functional outcomes, despite providing familiarity to surgeons accustomed to conventional instrumentation. LEVEL OF EVIDENCE: III.

Accelerometer-Based Navigation Is as Accurate as Optical Computer Navigation in Restoring the Joint Line and Mechanical Axis After Total Knee Arthroplasty: A Prospective Matched Study.

The Zimmer iASSIST system is a novel accelerometer-based navigation system for TKA. 76 patients (76 knees) were prospectively matched for age, BMI, gender, diagnosis, and pre-operative scores, and underwent TKA using the iASSIST (n=38) or optical CAS (n=38). There were no significant differences in clinical outcomes or satisfaction rates at six months post-operatively (P>0.05). Mechanical axis was 1.8±1.3° in the iASSIST cohort versus 2.1±1.6° in the CAS cohort (P=0.543). There were no significant differences in number of outliers for mechanical axis (P=1.000), coronal femoral-component angle (P=0.693), coronal tibial-component angle (P=0.204) or joint line deviation (P=1.000). The duration of surgery was significantly longer in the CAS group (P<0.001), while the added cost of accelerometer-based navigation was approximately $1000 per operation.