Effect of reverse manual wheelchair propulsion on shoulder kinematics,kinetics and muscular activity in persons with paraplegia

Objective: Shoulder pain after spinal cord injury (SCI) is attributed to increased mobility demands on the arms and negatively impacts independence and quality of life. Repetitive superior and posterior shoulder joint forces produced during traditional wheelchair (WC) locomotion can result in subacromial impingement if unopposed, as with muscular fatigue or weakness. ROWHEELS^® (RW), geared rear wheels that produce forward WC movement with backward rim pulling, could alter these forces.

Design: Cross sectional.

Setting: Research laboratory at a rehabilitation hospital.

Participants: Ten manual WC users with paraplegia.

Outcome measures: Propulsion characteristics and right upper extremity/trunk kinematics and shoulder muscle activity were collected during ergometer propulsion: (1) self-selected free speed reverse propulsion with RW, (2) matched-speed reverse (rSW), and (3) forward propulsion (fSW) with instrumented Smartwheels (SW). Inverse dynamics using right-side SW rim kinetics and kinematics compared shoulder kinetics during rSW and fSW.

Results: Free propulsion velocity, cycle distance and cadence were similar during RW, rSW and fSW. Overall shoulder motion was similar except that peak shoulder extension was significantly reduced in both RW and rSW versus fSW. Anteriorly and inferiorly directed SW rim forces were decreased during rSW versus fSW propulsion, but posteriorly and superiorly directed rim forces were significantly greater. Superior and posterior shoulder joint forces and flexor, adductor, and external rotation moments were significantly less during rSW, without a significant difference in net shoulder forces and moments. Traditional propulsive-phase muscle activity was significantly reduced and recovery-phase muscle activity was increased during reverse propulsion.

Conclusion: These results suggest that reverse propulsion may redirect shoulder demands and prevent subacromial impingement, thereby preventing injury and preserving independent mobility for individuals with paraplegia.     

The 2018 International Consensus Meeting Minor Criteria for Chronic Hip and Knee Periprosthetic Joint Infection: Validation From a Single Center

BackgroundRecently, a revised definition of the minor criteria scoring system for diagnosing periprosthetic joint infection (PJI) was developed by the second International Consensus Meeting on musculoskeletal infection. The new system combines preoperative and intraoperative findings, reportedly achieving high sensitivity and specificity. We aimed to validate the modified scoring system at a high-volume center.MethodsWe retrospectively reviewed patients who underwent a revision total hip or knee arthroplasty at our institution from May 2015 to August 2018. Serum C-reactive protein, synovial white blood cell count and polymorphonuclear percentage, leukocyte esterase test, alpha-defensin, microbiological and histologic results, and documented existence of sinus tract and intraoperative purulence were available for all patients. Cases with at least 1 major criterion were considered as infected. Using the new minor criteria, a score of ≥6 reflects PJI, while a score <3 can be considered as noninfected. Sensitivity, specificity, mean accuracy (ACC), positive predictive value (PPV), and negative predictive value (NPV) were analyzed.ResultsA total of 345 cases were included. A cutoff score of ≥6 points had the following diagnostic performance: area under the curve (AUC) = 0.90; ACC = 0.88; sensitivity = 0.96; specificity = 0.84; PPV = 0.70; NPV = 0.98. Diagnostic performance was better for the hip (AUC = 0.92; ACC = 0.90; sensitivity = 0.96; specificity = 0.86; PPV = 0.81; NPV = 0.98) than the knee (AUC = 0.89; ACC = 0.85; sensitivity = 0.95; specificity = 0.83; PPV = 0.59; NPV = 0.98).ConclusionThe modified scoring system proposed by the 2018 International Consensus Meeting in diagnosing PJI showed high sensitivity and a good performance, especially as rule-out diagnostic criteria. The cutoff level seems to be different between the hip and knee. Further validation studies considering the acknowledged limitations are recommended.     

Outcome and Predictors of Septic Failure Following Total Joint Arthroplasty for Prior Septic Arthritis of Hip and Knee Joint

BackgroundArthroplasty patients with prior septic arthritis are at a high risk of developing periprosthetic joint infection (PJI). The aims of this study are to investigate the outcome and predictors of septic failure following total joint arthroplasty (TJA) for prior septic arthritis. In addition, the optimal timing of TJA is also discussed.MethodsA retrospective review of 105 TJA patients with prior septic arthritis between January 2000 and December 2019 was performed. Patient-specific and surgery-related factors, organism profiles, and other relevant variables were recorded.ResultsAt a mean follow-up of 10.3 years, the PJI rate was 16.2%. The adjusted Cox proportional hazards model showed that male gender (HR, 9.95; P < .01), end-stage renal disease (HR, 37.34; P < .01), debridement surgery ≥3 times (HR,4.75; P = .04) and polymicrobial infection in primary septic arthritis (HR, 10.02; P = .02) were independent risk factors for PJI. Neither the types of initial debridement, nor one-stage vs two-stage arthroplasty was related to the risk of PJI. While delaying the timing of TJA did not correlate with a reduction of PJI rate, there was a higher risk of PJI re-infection by the same microorganisms isolated in prior septic arthritis if TJA was performed within 6 months after septic arthritis.ConclusionsOur study demonstrated that male gender, end-stage renal disease (ESRD), multiple debridement surgeries and polymicrobial septic arthritis predisposed septic failure of TJA following prior septic arthritis. Surgeons should counsel patients with the potential complications, and be cognizant about the risk factors pertaining to septic failure when considering TJA.     

脊髓空洞症合并Charcot关节病1例并文献复习

目的报告1例脊髓空洞症(SM)合并Charcot关节病(CJ),通过文献复习的方法提高对该病在诊断及治疗上的认识。方法通过回顾该疾病的临床表现及典型的影像学特点,结合相关文献以求提高诊断正确率。结果该病例左肘部为典型的Charcot关节病表现,颈椎MRI确诊为Chiari畸形合并脊髓空洞症。结论临床表现及影像学特点是诊断该病的主要依据,目前尚无有效治疗手段,手术治疗有一定疗效。