Post-retrieval functionality testing of PRECICE lengthening nails: The “Sleeper” nail concept

IntroductionPRECICE intramedullary magnetic lengthening nails, introduced in 2011, have changed the landscape of long bone limb lengthening. The implants have a stroke ranging from 5 to 8 cm, but it may be desirable to perform part of the lengthening at one treatment, allow bone healing, leave the implant in place, dormant, and then return one or more years later to re-lengthen with the same implant. We call this the “sleeper” nail concept. This strategy may be gentler for the joints and soft tissues. Would the nail mechanism still be functional one or more years later?MethodsWe tested 102 intact, consecutively explanted nails. Using a “fast magnet,” the male part was lengthened to 5 mm short of its maximum stroke capacity and retracted back to 35 mm (all nails start with the male part exposed 30 mm). The nails passed the test if the male part succeeded in lengthening to 5 mm short of the maximum stroke capacity and back to 35 mm (or only retract in case fully deployed at testing). During our testing, the nails were prevented from reaching their full capacity of lengthening/retraction to avoid jamming the gears. Failure was defined as the inability or partial ability to complete the process.ResultsEighty-six nails (84.3%) performed successfully according to our testing standard. When comparing successful and failed nails in terms of nail type, generation, diameter, length and in vivo interval, there was no statistical significance. Comparing both groups in terms of status at testing (fully deployed or not) showed statistical significance with 9 of the 16 failed nails fully deployed at testing (p < 0.001).ConclusionDormant PRECICE nails can be reactivated for further lengthening. The results imply that full deployment may damage the mechanism, making future re-use by retracting and then re-lengthening unsuccessful. The candidate nails for this purpose should not have any signs of clear damage (bending or breakage) and should not have been fully deployed. However, surgeons and patients should be aware of the need for possible nail exchange if the “sleeper” nail fails to wake up.Level of evidenceLevel IV case series analysis of retrieved surgical implants.     

Impacto del nivel socioeconómico sobre el perfil del paciente amputado de miembro inferior por causa no traumática

IntroductionTo analyse the influence of socioeconomic status on the clinical profile of patients undergoing non-traumatic lower-limb amputation.MethodsRetrospective study of 697 lower-limb amputee patients in an Angiology and Vascular Surgery Department during a 5-year period. Patients were classified according to their socioeconomic status (low, medium and high). We analysed demographic (age and gender) and clinical variables (cause of amputation, comorbidity, cardiovascular risk factors and amputation level).ResultsMean age was 70.5 ± 11.9 years, and the median was 72 years. The low socioeconomic status group presented a higher frequency of amputations in men. Cardiovascular risks factors were more frequent in this socioeconomic group, and the difference was statistically significant for diabetes (85.8% low, 69.3% medium, 65% high; P<.01) and obesity (31.4% low, 22.6% medium, 12.5% high, P<.01). Diabetic retinopathy was the only comorbidity with a significant association with low socioeconomic status (21.1% low, 15.3% medium, 12.5% high, P<.03). Regarding the cause for amputation, there was no difference in terms of socioeconomic status. The low socioeconomic level showed a higher frequency of major amputation, which was a significant difference (63.6% low, 41.2% medium, 55% high, P<.04) and a higher predisposition for this amputation level.ConclusionsThe low socioeconomic status has been shown to determine an unfavourable vascular risk profile in lower-limb non-traumatic amputees and a higher predisposition of a major amputation. This socioeconomic level demonstrates a negative influence on these patients’ diabetes, obesity and diabetic retinopathy.     

Clinical outcomes in pediatric tibial lengthening and deformity correction: a comparison of the Taylor Spatial Frame with the Orthex Hexapod System

PurposeComparison of two hexapod frame systems in paediatric tibial deformity correction; the Taylor Spatial Frame (TSF) and Orthex Hexapod System.MethodsPaediatric patients with congenital and acquired tibial deformities treated with either TSF (between 2014 and 2016) or Orthex (between 2017 and 2019) frames were included in a retrospective comparative study. Outcome measures were healing index, pin infection rate, regenerate quality and density, software residual rate, deformity correction accuracy, strut exchanges and quality of life (QoL).ResultsThe TSF group had 17 patients (18 frames) and the Orthex group had 21 patients (25 frames). The most common indications for tibial deformity correction were fibular hemimelia (14) and septic or traumatic growth arrest (8). The median time in frame was 230 days (TSF) versus 203 days (Orthex) (p= 0.06). The mean lengthening achieved was 54 mm (TSF) and 51 mm (Orthex) (p = 0.41). The healing index was 41 days/cm (TSF) versus 43 days/cm (Orthex) (p = 0.70). Pin site infections occurred more in the TSF cohort (40%) than in the Orthex cohort (18%) (p < 0.001). The regenerate in the Orthex group showed higher density at three months (p = 0.029) and was more homogenous (p = 0.023) at six months after frame application. Strut exchanges were less frequent with the Orthex system (p < 0.0001). QoL measures were similar in both cohorts (p = 0.92).ConclusionsThis is the first study to compare two hexapod designs in paediatric orthopaedics. The Orthex system showed superiority in regenerate quality and a significant reduction in pin site infection rates. Both systems delivered predictable and accurate limb deformity correction.Level of evidenceIII     

肢体负压对周围动脉闭塞性病变犬皮肤SP免疫反应阳性神经纤维影响

目的　观察肢体负压对周围动脉闭塞性病变犬皮肤中 SP免疫反应阳性神经纤维的影响 .方法　犬 17只 ,随机分治疗组 10只、非治疗组 5只和正常对照组 2只 ,治疗组和非治疗组均将动物制作左后肢缺血模型 ,治疗组在模型制作后 14d,开始行患肢负压治疗 10 d(15 min·次 - 1 ) ;非治疗组不做负压治疗 ;正常对照组不行缺血模型制作及负压治疗 . 3组均行左后肢趾皮肤免疫组化染色 ,检测 SP免疫反应阳性纤维 .结果　非治疗组皮肤中 SP免疫反应阳性神经纤维均较正常对照组明显增多 (P<0 .0 1) ,治疗组较非治疗组减少(P<0 .0 1) ,但仍较正常对照组增多 .结论　肢体负压疗法可促进皮肤感觉神经纤维中 SP的释放     

反复下体负压暴露对心脏泵血功能的影响

目的　探讨反复下体负压暴露对心脏泵血功能的影响及其与下体负压耐力的关系 .方法　 2 7名男性健康被试者随机分成 3组 ,分别进行 - 5 .33 k Pa 8min(A组 )、- 6 .6 7k Pa4min(B组 )、- 6 .6 7k Pa8m in(C组 )的下体负压锻炼 ,1次· d- 1 ,连续 8d,记录心率及血压 .锻炼前、后测量平卧位心脏泵血功能 .结果　 A组锻炼前后心脏功能各项指标无显著变化 (P>0 .0 5 ) ,B组锻炼后左室射血期 (L VET)、每搏输出量 (SV)、心输出量 (CO)、心指数 (CI)、血管顺应性 (C)分别为 :(2 97± 14) ms,(113± 37) m L,(7.3± 2 .3) L· min- 1 ,(4.2± 1.4) L·min- 1·m- 2 ,(2 .7± 1.0 ) m L·Pa- 1 ,较锻炼前显著增加 (P<0 .0 5 ) .而总外周阻力 (TPR)为 (7.6± 2 .9)L· Pa- 1·cm- 5,较锻炼前显著降低 (P<0 .0 5 ) .C组锻炼后较锻炼前上述指标变化趋势与 B组相同 ,但未达显著水平 .结论　 - 6 .6 7k Pa反复下体负压暴露可改善心脏泵血功能 ,其可能通过相对提高心水平动脉血压而提高下体负压耐力     

Motility Disorders after Roux-en-Y Gastrojejunostomy

About 30% of patients who have a Roux-en-Y gastrojejunostomy after gastrectomy suffer from abdominal pain, nausea, vomiting of food and bloating made worse by eating. This syndrome, called the Roux stasis syndrome, is caused, in part, by a motility disorder of the Roux limb. Transection of the jejunum during the construction of the limb separates the limb from the natural small intestinal pacemaker located in the duodenum. Ectopic pacemakers then appear in the limb and trigger retrograde contractions in its proximal portion. These contractions slow transit through the limb and result in Roux stasis. Current nonsurgical treatment of the syndrome includes the use of prokinetic agents and intestinal pacing, neither of which has demonstrated long-term benefits. A near-total gastrectomy may speed upper gastrointestinal transit somewhat, but stasis in the Roux limb often persists. Our current approach aims at preventing the syndrome by the use of an ‘uncut’ Roux limb, an operation which preserves myoneural continuity between the duodenal pacemaker and the Roux limb and so prevents the appearance of ectopic pacemakers and stasis in the limb.