Jason Beng Teck Lim

Aneurysmal Bone Cysts of the Vertebrae

Purpose. To review records of 14 patients with aneurysmal bone cysts (ABCs) of the spine. Methods. Using the Scottish Bone Tumour Registry for the period of October 1952 to November 2005, records of 9 females and 5 males aged 8 to 63 (mean, 25.3) years who had ABCs of the spine and were followed up for a mean of 7.1 years were reviewed. Results. The most commonly involved site was the lumbar vertebrae (n=6), followed by the thoracic (n=4), cervical (n=3), and sacral (n=1) vertebrae. The mean duration of symptoms at presentation was 8.8 (range, 0.3–24) months. The symptoms included gradually increasing pain in the back (n=14), a palpable spinal mass (n=4), spinal deformity (n=2), and neurological defcits (n=5). All the patients underwent surgery: intra-lesional excision (curettage) without bone grafting (n=3), excision (n=7, 2 of whom had adjuvant radiotherapy), and open excisional biopsy (n=4, 2 of whom had iliac crest bone grafting). One patient with a cervical ABC underwent preoperative angiographic embolisation. Another patient with a sacral ABC underwent percutaneous sclerotherapy. Two patients had recurrence. One had recurrence within 4 months and underwent adjuvant radiotherapy; another had recurrence 16.8 years later and underwent repeat curettage. No major complications were encountered. Conclusion. Most ABCs of the spine occurred in young females. Intra-lesional excision was an effective treatment.

Gender difference in outcome after total knee replacement.

Purpose. To compare the outcome after primary total knee replacement (TKR) for end-stage knee osteoarthritis (OA) in men versus women. Methods. Records of 214 men and 1040 women who underwent primary TKR for end-stage knee OA and were followed up for a minimum of 2 years were reviewed. Knee flexion, Oxford Knee Score, Knee Society Score (KSS), and 8 subscores of Short Form 36 (SF-36) were recorded preoperatively and at postoperative 6 months and 2 years. Results. Men and women were comparable only in age (67.9 vs. 67.3 years, p=0.244); men had a lower mean body mass index (27.0 vs. 28.3 kg/m2, p<0.001). Preoperatively, men had better knee flexion (117° vs. 114.8°, p=0.05), Oxford Knee Score (33.5 vs. 36.8, p<0.001), KSS knee score (44.3 vs. 40.3, p=0.001), KSS function score (52.5 vs. 47.1, p<0.001), and all 8 subscores of SF-36 (p=0.005 to p<0.001). Compared with men, women achieved greater improvement at 6 months in Oxford Knee score (13.2 vs. 15.1, p=0.009) and KSS knee score (36.9 vs. 41.6, p=0.016), and at 2 years in Oxford Knee Score (15.0 vs. 17.9, p<0.001), KSS knee score (39.8 vs. 43.9, p=0.009), and SF-36 subscores of social functioning (23.6 vs. 35.1, p<0.001) and mental health (3.9 vs. 8.2, p=0.003). Conclusion. Compared with men, women had poorer preoperative knee flexion, Oxford Knee Score, KSS, and 8 subscores of SF-36, but achieved greater improvement in the Oxford Knee Score and KSS knee score at 6 months and 2 years, as well as in SF-36 subscores of social functioning and mental health at 2 years.

Revision total knee arthroplasty for failed high tibial osteotomy and unicompartmental knee arthroplasty have similar patient-reported outcome measures in a two-year follow-up study

Aims Little is known about the relative outcomes of revision of unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) to total knee arthroplasty (TKA). The aim of this study is to compare the outcomes of revision surgery for the two procedures in terms of complications, re‐revision and patient‐reported outcome measures (PROMs) at a minimum of two years follow‐up. Patients and Methods This study was a retrospective review of data from an institutional arthroplasty registry for cases performed between 2001 and 2014. A total of 292 patients were identified, of which 217 had a revision of HTO to TKA, and 75 had revision of UKA to TKA. While mean follow‐up was longer for the HTO group compared with the UKA group, patient demographics (age, body mass index and Charlson co‐morbidity index) and PROMs (Short Form‐36, Oxford Knee Score, Knee Society Score, both objective and functional) were similar in the two groups prior to revision surgery. Outcomes included the rate of complications and re‐operation, PROMS and patient‐reported satisfaction at six months and two years postoperatively. We also compared the duration of surgery and the need for revision implants in the two groups. Results At two‐year follow‐up, both groups of patients had made significant improvement in terms of PROMs compared with pre‐operative scores. PROMs and satisfaction rates were similar in the two groups. Complications requiring re‐operation were significantly more frequent in the HTO group whilst more revision implants were used in the UKA group, resulting in a longer operative duration. Conclusion Revision of HTO and UKA achieve similar post‐operative PROMs and satisfaction. Revision of UKA more frequently requires revision components with increased operation duration but fewer complications requiring re‐operation compared with revision of HTO.

Preoperative Leg Pain Score Predicts Patient Satisfaction After Transforaminal Lumbar Interbody Fusion Surgery

Study Design: Retrospective cohort study. Objectives: This study aims to determine the preoperative predictors of postoperative satisfaction in transforaminal lumbar interbody fusion (TLIF) surgery in order to improve management of patient groups at high risk of dissatisfaction. We retrospectively reviewed prospectively collected data on patients who underwent open TLIF in a tertiary hospital between 2008 and 2012 with 2-year follow-up and performed multivariate analysis for their preoperative variables. Methods: A multivariate regression analysis was performed for the 217 patients to identify preoperative predictors of postoperative satisfaction. Clinical outcomes were evaluated using Oswestry Disability Index (ODI), North American Spine Society (NASS) Neurogenic Symptom Score (NSS), 36-item Short-Form Survey (SF-36; mean Physical and Mental Health scores), numerical pain rating scale (NPRS) for pain, and NASS Questionnaire. Results: Significant improvements were seen in the postoperative ODI, NSS, SF-36, and NPRS scores at 2 years (P < .05). Eighty-six percent of the patients had their expectations of surgery met, and 94.7% of the patients were satisfied with the results of treatment at 2 years. From the multivariate regression model, patients with higher preoperative NPRS pain score (odds ratio = 1.323; 95% confidence interval = 1.071-1.633; P = .009) was more likely to be satisfied at 2 years. Conclusions: TLIF surgery provided significant health-related quality-of-life scores and symptom improvement in terms of SF-36, ODI, NSS, and NPRS, with a high proportion of patients being satisfied with the results of surgery. Patients with higher preoperative NPRS leg pain were more likely to be satisfied at 2 years. Patient-reported satisfaction may be largely influenced by the improvement of radicular leg pain.

What Are the Preoperative Outcome Measures That Predispose to Periprosthetic Fractures After Primary Total Knee Arthroplasty

BACKGROUND There is little known in the literature about whether preoperative patient-reported outcome measures (PROMs) would affect the risk of periprosthetic fractures (PPFs) after primary total knee arthroplasty (TKA). Our study aims to evaluate the predictive values of PROMs on PPF after primary TKA. We hypothesize that poorer PROMs are associated with a higher risk of PPF after primary TKA. METHODS We reviewed prospectively collected data in our hospital arthroplasty registry. Patients who sustained PPF after primary TKA between 2000 and 2015 were identified. Forty-two patients were identified and matched for gender, age, and body mass index to a control group of 84 patients who had primary TKA without PPF in a 2:1 ratio. Preoperative demographics, Short Form-36 (SF-36) scores, Oxford Knee score and Knee Society Score were evaluated. Variables of PROMs were entered into a multivariate logistic regression model. A variable was considered to be a significant predictor if its odds ratio was significant at P < .05. RESULTS After multivariate regression analysis, SF-36 subdomains of physical functioning (PF) and vitality (VT) were identified as significant predictors for PPFs after primary TKA. A lower SF-36 PF and VT scores were associated with higher risks of sustaining a PPF after primary TKA. CONCLUSION From our study, low preoperative SF-36 PF and VT scores are associated with a higher risk of PPFs after primary TKA. These results can allow the preoperative identification of patients at higher risk of PPF, and appropriate preoperative counseling, optimization, and close follow-up can be instituted for this at-risk group.

Gender-specific total knee arthroplasty in Singaporean women.

Purpose. To compare the outcome of 145 women who underwent conventional total knee arthroplasty (TKA) with 77 women who underwent gender-specific TKA. Methods. Records of 222 women who underwent primary TKA using a conventional (n=145) or gender-specific (n=77) size E or F prosthesis for end-stage osteoarthritis were reviewed. The gender-specific prosthesis has a narrower mediolateral dimension. Patients were assessed for flexion, Oxford Knee Score, Knee Society function and knee scores, and Short Form–36 Health Survey preoperatively and postoperatively (at 6 months and 2 years). Results. The 2 groups were comparable in terms of age (67.8 vs. 68.1 years, p=0.789), body mass index (28.6 vs. 27.8 kg/m2, p=0.189), and preoperative scores. 12 women with conventional TKA and 4 women with gender-specific TKA were lost to follow-up. Compared with women with conventional TKA, women with gender-specific TKA had better flexion at 6 months (116° vs. 121.9°, p=0.007) and 2 years (118.7° vs. 124.6°, p=0.006), better bodily pain score at 2 years (65.1 vs. 72.4, p=0.049), and greater improvement in bodily pain score from baseline to 2 years (30 vs. 38.5, p=0.034). Conclusion. Gender-specific TKA enables better knee flexion and less bodily pain in women who have a high propensity to develop mediolateral overhang of the femoral component.