Forgotten Joint Score Post Total Knee Arthroplasty and Its Correlation with the New Knee Society Score.

BACKGROUND/PURPOSE: Forgotten Joint Score (FJS) is designed to asses patient recovery post Total Knee Arthroplasty (TKA) in a new dimension. It assess the ability to forget the operated joint as artificial during activities of daily living. New Knee Society Score (NKSS) is developed to encompass objective and subjective outcome as well as an assessment of patient expectation and satisfaction. Our purpose was (1) to determine FJS at 1 year post TKA in Indian Patients, and (2) to assess convergent validity between FJS and the NKSS. We hypothesised that FJS should strongly correlate with the Satisfaction (SS) and Knee perception(KPS) sub-component of NKSS. METHODS: We enrolled 181 patients who underwent primary TKA during an 8-month duration. They were prospectively followed up at 1-year review clinic when FJS and NKSS were administered. 169 patients completed the assessment forms and 13 patients were lost to follow-up. Statistical evaluation was done with Spearman correlation test. RESULTS: Mean FJS at 1 year was 66.6 ± 25.9 with 14% ceiling and 1% floor effects. There was a mild to moderate correlation of FJS with NKSS (p < 0.001, r = 0.47) and its sub-scores (p < 0.001; r = 0.43 and r = 0.44). There was a weak correlation of FJS with NKSS sub-components of SS and KPS (p < 0.001; r = 0.37 and 0.25, respectively). CONCLUSION: Mean FJS at 1 year post TKA showed convergent validity with NKSS; however, the correlation was not strong enough to use them interchangeably. Hypothesis that FJS should strongly correlate with the NKSS sub-components of satisfaction and joint perception was refuted. We conclude, FJS provides unique evaluation in recovery post TKA, different from NKSS. LEVEL OF EVIDENCE: Level III.

WHO Class of Obesity Influences Functional Recovery Post-TKA.

BACKGROUND: No study in the literature has compared early functional recovery following total knee arthroplasty (TKA) in the obese with the nonobese using World Health Organization (WHO) classes of obesity. Our aim was to compare functional scores and flexion post-TKA in each class of obesity as per WHO classification against a matched control group of nonobese patients. METHODS: Records of 885 consecutive primary TKA patients (919 knees) operated by a single surgeon were reviewed. The first 35 knees in each class I, class II and class III obesity group during the study period were then matched with a similar number of knees in nonobese TKA patients during the same period. Functional scores recorded pre- and postoperatively at 3 months and 1 year were Western Ontario and McMaster Osteoarthritis Index (WOMAC), Short-Form Health Survey (SF-12) score, and Knee Society Score (KSS). RESULTS: There was no difference in any parameter between the class I obese and matched nonobese at any assessment point. In the class II obese, as compared to the nonobese, there was no difference in any parameter preoperatively and 3 months postoperatively. However, 1 year postoperatively, the SF-12 physical subscore was lower in the class II obese than the nonobese (44.7 vs. 48.6, p = 0.047) and the WOMAC score was significantly higher (15.8 vs. 9.7, p = 0.04). In the class III obese, the WOMAC score was significantly higher than the nonobese (58.1 vs. 44.3, p < 0.001 preoperatively; 15.7 vs. 8.1, p = 0.005 at 1 year) and KSS was significantly lower (83.5 vs. 96.5, p = 0.049 preoperatively; 172 vs. 185; p = 0.003 at 1 year). Knee flexion was significantly lower in the class III obese than the nonobese (95 vs. 113; p < 0.001 preoperatively; 120 vs. 127; p = 0.002 at 1 year). CONCLUSIONS: The class I obese can expect good early and late functional recovery as the nonobese. The class II obese can expect comparable early functional recovery as the nonobese but their late function may be lesser. The class III obese would have poorer functional scores and lesser knee flexion postoperatively compared to the nonobese. However, compared to their own preoperative status, there is definite improvement in function and knee flexion.

What is the Responsiveness and Respondent Burden of the New Knee Society Score?

BACKGROUND: Although the new Knee Society score (NKSS) has been validated by a task force, a longitudinal study of the same cohort of patients to evaluate the score's responsiveness and respondent burden has not been reported, to our knowledge. QUESTIONS/PURPOSES: We analyzed the NKSS for (1) responsiveness; (2) respondent burden; and (3) convergent validity in 148 patients studied longitudinally during more than 1 year. METHODS: During an 8-month period, 165 patients underwent TKA by the same surgeon at our institution, of whom 148 (90%) completed this study; the others were excluded because of distance to travel or loss to followup at the specified time. The NKSS, WOMAC, and SF-12 were completed by each patient 1 day before surgery and at 3 and 12 months postoperatively. At the same times, the original KSS (OKSS) which is designed as an observer's assessment, was completed by the same orthopaedic fellow for all patients. Responsiveness of the NKSS was assessed by determining effect size, standardized response mean (SRM), and ceiling and floor effects. Respondent burden was assessed through time to completion recorded in minutes and ease of completion which was measured objectively on a Likert scale of 1 to 5 by the patients. Convergent validity was assessed by correlating the NKSS with the WOMAC, SF-12, and OKSS (current, widely used scales) by Pearson's correlation coefficient. RESULTS: Effect size was largest (2.83 and 3.38) and SRM was highest (2.29 and 2.68) for the NKSS at 3 and 12 months respectively, indicating the NKSS to be the most-responsive score followed by the OKSS, WOMAC, and SF-12. The NKSS exhibited no ceiling and floor effects. The NKSS took a longer time to complete (5.49 ± 3.56 minutes) compared with the WOMAC (4.64 ± 3.19 minutes) and SF-12 (4.35 ± 3.27 minutes). The mean difference in time taken for the NKSS versus the WOMAC was 0.85 minutes (95% CI, 0.54-1.17 minutes; p < 0.001) and the mean difference for the NKSS versus the SF-12 was 1.14 minutes (95% CI, 0.76-1.15 minutes; p < 0.001). Its ease of completion generally was comparable to that of the WOMAC and SF-12. Convergent validity showed a strong correlation (r > 0.6; p < 0.001) of the NKSS with the WOMAC at all times and moderate to strong correlation (r = 0.4-0.6; p < 0.001) with the SF-12 and OKSS at the first two assessments, which became strong (r > 0.6; p < 0.001) at 12 months. CONCLUSIONS: The NKSS exhibited greater responsiveness than the WOMAC, SF-12, and OKSS scales and showed no ceiling effect, indicating adequate potential for recording future improvement. The NKSS also showed reliable convergent validity when correlated with these other scores. However, it posed a greater respondent burden in terms of time to completion. CLINICAL RELEVANCE: As independent nondevelopers of the NKSS, we found it to be a responsive tool for assessment of TKA outcomes. We have confirmed that the NKSS can be used interchangeably for this purpose with the WOMAC scale and that it correlates positively with other established scales of the SF-12 and OKSS. Further study of the short-form version will establish whether it also can be used effectively while reducing the respondent burden.

A prospective randomized study in 20 patients undergoing bilateral TKA comparing midline incision to anterolateral incision.

BACKGROUND: Lateral flap numbness is a known side-effect of midline skin incision in total knee arthroplasty (TKA) and a cause of patient dissatisfaction. Anterolateral incision is an alternative approach which preserves the infrapatellar branches of the saphenous nerve and avoids numbness. Studies have compared both incisions, but in different patients. However, different patients may assess the same sensory deficit dissimilarly, because of individual variations in anatomy and healing responses. We compared the two incisions in the same patient at the same time, using an anterolateral incision on one knee and a midline incision on the other knee in simultaneous bilateral TKA. Other surgical steps including medial arthrotomy were idential. We also correlated subjective and objective findings. MATERIALS AND METHODS: Twenty patients were prospectively randomized. Sensory loss and skin healing were assessed at 6, 12 and 52 weeks. Subjective preference for the knee with less numbness was charted on Wald's Sequential Probability Ratio Test. Sensation scores for touch, vibration, static and moving two-point discrimination were measured. Scar healing was evaluated using the Patient and Observer Scar Assessment Scale (POSAS). Functional scores were measured. RESULTS: A statistically significant difference favoring knees with anterolateral incision was observed in patient preference at all assessment points and this correlated with sensation scores. A statistically significant difference was observed in POSAS score favoring knees with anterolateral incision at 6 and 12 weeks which became statistically insignificant at 1 year. Functional scores remained comparable. CONCLUSION: We recommend anterolateral incision as a safe and effective method to circumvent the problem of lateral flap numbness with midline incision. LEVEL OF EVIDENCE: I.

Ten- to 13-Year Results of Mobile Bearing Posterior-Stabilized Rotating-Platform Knee Implants, Reported by Nondesigner Surgeon.

BACKGROUND: Posterior-stabilized rotating-platform (PSRP) knee was designed with the purpose of improving postoperative flexion and stability. Its long-term performance has limited reports, which could show whether this purpose has been realized without deleterious effect. We report its long-term results at 10-13 years, of a previously studied cohort, evaluated longitudinally. METHODS: A total of 133 consecutive PSRP implants, selected for 118 patients were studied. Twenty-one patients (24 knees) were deceased and 11 patients (12 knees) were lost to follow-up after 10 years. Eighty patients (97 knees) completed clinical evaluation, of whom 78 patients (88 knees) also completed radiological evaluation. RESULTS: Mean flexion improved from 106.8° (30°-150°) to 127° (90°-155°). Forty-three percent patients could sit crosslegged, 32.5% could sit on floor, and 3.4% could squat. Mean knee subscore of Knee Society Score improved from 28 (1-59) to 96 (67-100). Mean function subscore improved from 53 (5-81) to 78 (-10 to 100). After 10 years, 5 patients had zero function score because of developing other debilitating medical illnesses. Twenty-one dead patients (24 knees), at their last follow-up (7.7 years), had satisfactory scores. No patient had spinout or revision. Radiologically, alignment was satisfactory and there was no osteolysis. Kaplan-Meier analysis showed 100% implant survival. CONCLUSION: PSRP design, evaluated after 10 years of implantation in selected patients, had 100% survival with good flexion. Addition of post and cam to the original rotating platform design has provided good stability without untoward effects of wear or osteolysis at 10-13 years.

Mid term results of LCS knee: The Indian experience.

BACKGROUND: The low contact stress rotating platform (LCS RP) knee (DePuy Orthopedics, Inc, Warsaw, Indiana), in use for last four decades in Western population, is reported to have a survival of more than 95% at 15 to 20 years. The reported Indian experience of this knee is limited to 5 years. Our aim was to report the clinical and radiological results of the LCS RP TKA design in the Indian population with a minimum followup of 10 years. MATERIALS AND METHODS: Fifty-five LCS knees (45 patients) operated between February 1997 and October 2001 were evaluated retrospectively. LCS design was generally selected if the patient was young (≤65 years of age), active and had no severe deformity. There were 40 female (88.9%) and 5 male (11.1%) patients; 47 knees had osteoarthritis (85.5%) and 8 knees had rheumatoid arthritis (14.5%). Knee Society Scores (KSS) and outcome questionnaire were filled at followup and radiographs were analyzed using Knee Society radiographic evaluation and scoring system. RESULTS: Of 45 patients (55 knees) enrolled, 37 patients (44 knees; 80%) were available for followup at 10 years. Average age was 59.6 years (range 40 to 77). Minimum followup was 10 years (average 12.3 years; range 10 to 15.3 years.). Three knees (6.8%) had been revised, one each for aseptic loosening, bearing dislocation and infection. Mean preoperative KSS of 33 improved to 91 postoperatively. Mean preoperative functional score of 45 improved to 76 postoperatively. Mean preoperative flexion of 113° (90°-140°) reduced to 102° (80°-135°) postoperatively. Erratic femoral rollback and tighter flexion gap to prevent spin out are the probable factors for decreased postoperative range of motion. Five (12%) patients could sit cross-legged and sit on the floor. Anterior knee pain was present in 4.6% (2/44 knees). The survival was 93.2% at 12.3 years. One patient (1.8%) had spin-out of the rotating bearing. No knee had osteolysis or progressive radiolucent lines on X-rays. CONCLUSION: LCS implant has given good survival (93.2% at 12.3 years) with low rates of spin-out and anterior knee pain and no incidence of osteolysis. Limited flexion post surgery (104°) with only 12% managing to sit cross legged on the floor is a drawback.

Most effective regimen of tranexamic acid in knee arthroplasty: a prospective randomized controlled study in 240 patients.

BACKGROUND: The antifibrinolytic tranexamic acid reduces surgical blood loss, but studies have not identified an optimal regimen. QUESTIONS/PURPOSES: We studied different dosages, timings, and modes of administration to identify the most effective regimen of tranexamic acid in achieving maximum reduction of blood loss in TKA. METHODS: We prospectively studied five regimens (four intravenous, one local; 40 patients each) with a control group (no tranexamic acid). The four intravenous (10-mg/kg dose) regimens included (1) intraoperative dose (IO) given before tourniquet deflation, (2) additional preoperative dose (POIO), (3) additional postoperative dose (IOPO), and (4) all three doses (POIOPO). The fifth regimen was a single local application (LA). Two independent parameters of drain loss and total blood loss, calculated by the hemoglobin balance method, were evaluated statistically. RESULTS: Both parameters were reduced in all five regimens as against the control. A significant reduction in drain loss was seen in the POIO, IOPO, and POIOPO groups whereas total blood loss was significantly reduced in the POIO, POIOPO, and LA groups. The POIOPO group had the least drain loss (303 mL) and least total blood loss (688 mL). The IO group had the greatest drain loss and the IOPO group the greatest total blood loss. CONCLUSIONS: Single-dose tranexamic acid did not give effective results. The two-dose regimen of POIO was the least amount necessary for effective results. When compared against the control, this regimen produced reduction of drain loss and total blood loss, whereas the IOPO regimen did not. The three-dose regimen of POIOPO produced maximum effective reduction of drain loss and total blood loss.