Coccygectomy for refractory coccydynia, old-fashioned but effective procedure: A retrospective analysis.

PURPOSE: Coccydynia, characterized by persistent pain in the coccygeal region, significantly impacts patients' quality of life. While various treatment modalities exist, including conservative measures and surgical interventions like coccygectomy, optimal management remains unclear. This retrospective cohort study aimed to compare the clinical outcomes, functional improvements, and quality of life in patients with chronic coccydynia undergoing either infiltrative treatment or coccygectomy. METHODS: Data from patients treated at our institution from January 2018 to December 2022 were analyzed. Participants meeting inclusion criteria were divided into two groups: Group A underwent coccygectomy, while Group B received conservative therapy. Clinical assessments, radiographic evaluations, and patient-reported outcomes were collected preoperatively and at follow-up intervals. RESULTS: Of the 223 initially examined patients, 55 met inclusion criteria. Group A (n = 21) underwent coccygectomy, while Group B (n = 34) received conservative therapy. Both groups showed significant pain reduction post-intervention, with sustained improvement in Group A. Functional outcomes favoured Group A, with significant improvements in disability and quality of life measures. Complications were minimal, with only one case of superficial wound infection in Group A. CONCLUSION: Our findings suggest that coccygectomy provides superior and lasting pain relief, functional improvement, and quality of life improvement compared to conservative therapy. While complications were minimal, further research with larger cohorts is warranted to validate these results and explore long-term outcomes. Despite its historical association with complications, advancements in surgical techniques and perioperative care have led to improved outcomes and reduced complication rates. Thus, coccygectomy should be considered in the treatment algorithm for patients with debilitating coccydynia.

Does primary tumor resection improve survival for patients with sarcomas of pelvic bones, sacrum, and coccyx who have metastasis at diagnosis ?

BACKGROUND: Recent studies demonstrated that primary tumor resection (PTR) improves survival of patients with metastatic bone sarcomas. However, it remains quite unclear regarding the role of PTR in the treatment of sarcomas of pelvic bones with synchronous metastasis at diagnosis. METHODS: Using the Surveillance, Epidemiology, and End Results Program, we enrolled a total of 385 patients with sarcomas of pelvic bones, sacrum, and coccyx who have metastasis at initial diagnosis, including 139 patients with osteosarcoma, 176 with Ewing sarcoma, and 70 with chondrosarcoma. Association between PTR and disease-specific survival (DSS) were investigated using the univariable and multivariable Cox regression models. Hazard ratio (HR) and 95% confidence interval (CI) were reported. Representative institutional PTR strategies and clinical outcomes for patients with metastatic pelvic sarcomas from our cancer center were displayed. RESULTS: The usage rate of PTR was 28.1% (39/139) in osteosarcoma, 13.6% (24/176) in Ewing sarcoma, and 41.4% (29/70) in chondrosarcoma with synchronous metastatic lesions. PTR was not associated with an improved DSS for metastatic pelvic osteosarcoma (HR = 0.686, 95% CI = 0.430 ~ 1.094, P = 0.113) and Ewing sarcoma (HR = 0.580, 95% CI = 0.291 ~ 1.154, P = 0.121). The use of PTR was associated with an improved DSS for metastatic pelvic chondrosarcoma (HR = 0.464, 95% CI = 0.225 ~ 0.954, P = 0.037). CONCLUSION: Primary lesion resection may provide a survival benefit for metastatic chondrosarcoma, but not for osteosarcoma and Ewing sarcoma of pelvic bones, sacrum, and coccyx. This population-based study recommends an active surgical intervention for metastatic chondrosarcoma while non-surgical treatment for metastatic osteosarcoma and Ewing sarcoma of the pelvis in terms of survival improvement.

Ontogeny of the anuran urostyle and the developmental context of evolutionary novelty.

Developmental novelties often underlie the evolutionary origins of key metazoan features. The anuran urostyle, which evolved nearly 200 MYA, is one such structure. It forms as the tail regresses during metamorphosis, when locomotion changes from an axial-driven mode in larvae to a limb-driven one in adult frogs. The urostyle comprises of a coccyx and a hypochord. The coccyx forms by fusion of caudal vertebrae and has evolved repeatedly across vertebrates. However, the contribution of an ossifying hypochord to the coccyx in anurans is unique among vertebrates and remains a developmental enigma. Here, we focus on the developmental changes that lead to the anuran urostyle, with an emphasis on understanding the ossifying hypochord. We find that the coccyx and hypochord have two different developmental histories: First, the development of the coccyx initiates before metamorphic climax whereas the ossifying hypochord undergoes rapid ossification and hypertrophy; second, thyroid hormone directly affects hypochord formation and appears to have a secondary effect on the coccygeal portion of the urostyle. The embryonic hypochord is known to play a significant role in the positioning of the dorsal aorta (DA), but the reason for hypochordal ossification remains obscure. Our results suggest that the ossifying hypochord plays a role in remodeling the DA in the newly forming adult body by partially occluding the DA in the tail. We propose that the ossifying hypochord-induced loss of the tail during metamorphosis has enabled the evolution of the unique anuran bauplan.

[Coccygodynia-An often underestimated clinical picture]. / Kokzygodynie ­ ein häufig unterschätztes Krankheitsbild.

One of the most frequently underestimated symptoms in orthopedic practices is coccygodynia. The clinical picture of coccygodynia was first described in 1859. Nevertheless, discussions about the importance of coccygeal problems remain a controversial topic. All patients have in common that they have gone through a long ordeal with many therapists, examinations and therapeutic approaches without having received a real diagnosis. The main symptom of coccygodynia is pain directly on the lowest segment of the coccyx, which often only occurs when sitting and is intensified by a change in position, usually from a sitting to a standing position. Trauma can only be described as the trigger in 50% of cases. Women are four times more likely to be affected than men. The gold standard for imaging should be viewed from standing and seated dynamic lateral radiographs of the coccyx. After the diagnosis has been made, conservative treatment should first be started with oral nonsteroidal anti-inflammatory drugs (NSAID), relief with a coccyx cushion with a recess and, if necessary, physiotherapy to strengthen or loosen the pelvic floor. Local infiltration with a glucocorticoid and a local anesthetic directly in the painful area are also often promising. If the symptoms persist for more than 6 months, surgical treatment in the sense of removing the coccyx can be discussed with the patient. The literature shows a success rate of 80-90% if the indications are correct.

Minimally Invasive Open Reduction and Maintenance Technique for Anterior Sacrococcygeal Dislocation: A Case Report.

Anterior dislocation of the coccyx is rare, but it can occur due to trauma. Conservative treatment is usually performed. However, dislocation reduction may be required to control severe pain in the acute phase or to prevent chronic complications. If manual reduction fails, open reduction is required. The extent of the incision and the method used to maintain the reduction should be considered during open reduction. A 56-year-old male patient experienced a dislocation of the sacrococcygeal joint after falling backwards. Despite conservative treatment, the patient complained of persistent pain during sitting and when using the bathroom. A manual reduction was attempted but failed. We performed joystick reduction via minimal incision and maintained the reduction using a one-strand trans-osseous suture passing through the skin. The patient was advised to use a soft cushion when sitting or lying down for four weeks after surgery. The supine position was not restricted. The patient's symptoms significantly improved after surgery. At the 6-month follow-up, the sacrococcygeal joint showed good alignment and no surgical complications occurred. During the treatment of sacrococcygeal dislocation, the rapid alleviation of acute pain and minimizing potential complications are key points. If open reduction is needed, the minimally invasive reduction technique with a one-strand trans-osseous suture may offer patient satisfaction and a good surgical outcome.

A novel radiological classification for displaced os coccyx: the Benditz-König classification.

BACKGROUND: Treatment of coccygodynia is still a challenging entity. Clear surgical selection criteria are still lacking. The aim of the investigation was to establish a novel radiological classification for surgical decision-making in coccygodynia cases. MATERIAL AND METHODS: Retrospective analysis of standing and sitting X-rays of coccygodynia patients referred to a single centre from 2018 to 2020. The sacro-coccygeal angle (SCA), the intra-coccygeal angle (ICA) and the difference of the intervertebral disc height (∆IDH) were measured. All coccyges were distributed in subtypes and correlated with the patients' treatment. RESULTS: In total, 138 patients (female/male: 103/35) with a mean age of 45.6 ± 15.4 years were included in the study. In total, 49 patients underwent coccygectomy. Four different subtypes of displaced coccyges were identified: Type I with a non-segmented coccyx, anterior pivot, increased SCA and ICA from standing to sitting, ∆IDH = 1.0 ± 1.5 mm. Type II with a multisegmented coccyx, anterior pivot, increased SCA and ICA standing/sitting, ∆IDH = 1.1 ± 1.6 mm. Type III showed a posterior pivoted coccyx, negative SCA and ICA, ∆IDH = 0.6 ± 1.6 mm. Type IV is characterized by an anterior-posterior dissociation of the tail bone with a positive SCA, and the ICA shifted from a posterior to an anterior orientation. ∆IDH was - 0.6 ± 1.8 mm. CONCLUSION: The presented radiological classification could help to facilitate the surgical decision-making for patients with displaced os coccyx. In addition, lateral and sitting X-rays were easy to perform and did not need unnecessary ionizing radiation like in CT scans and were more cost-effective than MRI investigations. The subtypes III and especially IV were more likely leading to surgery.

Coccygectomy for refractory coccygodynia: a systematic review and meta-analysis.

PURPOSE: We sought to systematically assess and summarize the available literature on outcomes following coccygectomy for refractory coccygodynia. METHODS: PubMed, Scopus, and Cochrane Library databases were systematically searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data concerning patient demographics, validated patient reported outcome measures (PROMs) for pain relief, disability outcomes, complications, and reoperation rates were extracted and analyzed. RESULTS: A total of 21 studies (18 retrospective and 3 prospective) were included in the quantitative analysis. A total of 826 patients (females = 75%) received coccygectomy (720 total and 106 partial) for refractory coccygodynia. Trauma was reported as the most common etiology of coccygodynia (56%; n = 375), followed by idiopathic causes (33%; n = 221). The pooled mean difference (MD) in pain scores from baseline on a 0-10 scale was 5.03 (95% confidence interval [CI]: 4.35 to 6.86) at a 6-12 month follow-up (FU); 5.02 (95% CI: 3.47 to 6.57) at > 12-36 months FU; and 5.41 (95% CI: 4.33 to 6.48) at > 36 months FU. The MCID threshold for pain relief was surpassed at each follow-up. Oswestry Disability Index scores significantly improved postoperatively, with a pooled MD from baseline of - 23.49 (95% CI: - 31.51 to - 15.46), surpassing the MCID threshold. The pooled incidence of complications following coccygectomy was 8% (95% CI: 5% to 12%), the most frequent of which were surgical site infections and wound dehiscence. The pooled incidence of reoperations was 3% (95% CI: 1% to 5%). CONCLUSION: Coccygectomy represents a viable treatment option in patients with refractory coccygodynia.

Anococcygeal Nerve and Sitting Pain: Differential Diagnosis and Treatment Results.

BACKGROUND: The plastic surgeon is often asked to reconstruct the sacral area related to pilonidal cysts or a tumor, or after other surgery, such as coccygectomy. When sitting pain is not due to the pudendal or posterior femoral cutaneous nerve injury, the anococcygeal nerve (ACN) must be considered. Clinically, its anatomy is not well known. Rather than consider coccygectomy when the traditional nonoperative treatment of coccydynia fails, resection of the ACN might be considered. METHODS: A review of traditional anatomy textbooks was used to establish classical thoughts about the ACN. A retrospective cohort of patients with sitting pain related to the coccyx was examined, and those operated on, by resecting the ACN, were examined for clinicopathologic correlations. RESULTS: When the ACN is described in anatomy textbooks, it is with varying distributions of innervated skin territory and nerve root composition. Most include an origin from sacral 5 and coccygeal 1 ventral roots. Most agree that the ACN forms on the ventral side of the sacrum/coccyx, alongside the coccygeus muscle, to emerge laterally and travel dorsally to innervate skin over the coccyx and lower sacrum. A review of 13 patients with sitting pain due to the ACN, from 2015 to 2019, demonstrated a mean age of 54.6 years. Eleven were female. The etiologies of ACN injury were falls (9), exercise (3), and complication from surgery (1). Six of the 9 patients who had surgery were able to be followed up with a mean length of 36.3 months (range, 11-63 months). Overall, 3 had an excellent result, 2 had a good result, and 1 was not improved. The one with a failed result showed improvement with coccygectomy. CONCLUSIONS: The ACN must be included in the differential diagnosis of sitting pain. It is most often injured by a fall. The ACN can be evaluated with a diagnostic nerve block, can be identified at surgery, and can be resected, and its proximal end can be implanted into the coccygeus muscle. This surgery may prove an alternative to coccygectomy.

[Coccygodynia: Case Reports and Literature]. / Coccygodynie: vlastní kazuistiky a prehled literatury.

Coccygodynia, or tailbone pain, is the most common in women after trauma (complicated childbirth, fall). This pain can be treated conservatively (by using analgesics, local injections, physiotherapy) or by surgical coccygectomy. In the presented article, a set of five female patients is evaluated, in whom, after the failing conservative therapy, coccygectomy was indicated for persistent coccygodynia. In all female patients, improvement of their clinical condition and alleviation of pain were reported. Coccygectomy has its place in the management of coccygodynia and in correctly chosen patients significant pain reduction can be expected. Key words: coccygodynia, coccyx, coccygectomy, trauma.

Conservative treatment for chronic coccydynia: a 36-month prospective observational study of 115 patients.

PURPOSE: To describe long-term outcomes of conservative treatment for chronic coccydynia. METHODS: We conducted a 36-month prospective observational study. Adults with chronic coccydynia (> 2 months) were included. The first-line treatment was coccygeal corticosteroid injection. The second-line treatment was either manual therapy or coccygectomy. The primary endpoint was the mean variation from baseline of coccydynia intensity at 6 and 36 months, using a numeric rating scale (0, no pain; 10, maximal pain). Evolution was considered unfavorable when coccydynia intensity was > 3 of 10 points at 36 months or coccygectomy had been performed. We carried out bivariate and multivariate analyses to identify variables associated with an unfavorable evolution. RESULTS: We included 115 participants. Mean (SD) age was 43.5 (12.3) years, duration of coccydynia 18.4 (21.6) months and coccydynia intensity 6.5 (2.0) of 10 points. Mean variations for coccydynia intensity were - 1.5 (3.0) at 6 months and - 2.8 (3.2) at 36 months. At 36 months, 59/115 (51%) participants had an unfavorable evolution. In bivariate analysis, posterior coccyx dislocations were numerically more frequent in participants with an unfavorable evolution compared to others (29/59 (48%) versus 17/56 (30%), p = 0.057). In multivariate analysis, longer duration of coccydynia was associated with an unfavorable evolution (OR = 1.04, 95% CI from 1.01 to 1.07, p = 0.023). CONCLUSION: In adults with chronic coccydynia receiving conservative treatment, symptoms decrease overtime, but significantly persist at 36 months in more than half of them. For patients with posterior coccyx dislocation, coccygectomy may be considered rapidly.

Coccygectomy for coccygodynia: a cohort study with a long-term follow-up of up to 29 years.

PURPOSE: We aim to critically review the effectiveness and safety of coccygectomy with special regard to long-term outcomes. METHODS: Coccygectomy was performed in our clinic in 38 patients between 1990 and 2019. All these patients (32 females vs. 6 males) have failed to respond to conservative treatment for at least 6 months prior to surgery. All patients were available for follow-up after mean 12,3 years (2 months to 29 years, 11 patients had a minimum FUP of 24 years). We evaluated all patients clinically and radiologically. RESULTS: Nineteen patients reported traumatic and 17 patients reported idiopathic onset of their symptoms; one patient had clinical symptoms after childbirth and another patient had coccygodynia after extensive low back surgery. 36 of our 38 patients were free of pain at least 6 months after surgery and had good or excellent clinical results according to the VAS which improved from 6.37 (SD 1.08) preoperatively to 0.68 (SD 0.99) at the recent follow-up. Two patients showed an ODI > 22 at the recent follow-up (24 and 28) and 32 had an ODI equal or under 4. There was no statistical significant difference in terms of clinical outcome between the different radiological types of the coccyx. Postoperative complications were rare: 1 superficial infection and one re-operation 6 months after initial surgery due to an pre-existing exostosis which had not been removed at the index surgery; no neurological complications and no major bleeding occurred. No patient had recurrent onset of coccygodynia. 37 out of 38 patients would have coccygectomy again. CONCLUSIONS: Coccygectomy is a safe treatment option in patients with coccygodynia and shows excellent long-term results. We recommend to perform coccygectomy if patients fail to respond to conservative treatment for 6 months. LEVEL OF EVIDENCE: IV.

Varied parameters and utility of the anal position index: a systematic review and meta-analysis.

PURPOSE: The anal position index (API) was described in 1984 by Reisner et al. Since then, it has been measured in different ethnic populations and its utility in various medical conditions have been explored. We aimed to review the literature regarding the various values reported analytically. METHOD: A Pubmed Search was carried out with the terms Anal Position Index. There were 158 articles hit by the search. The description of the API was uniform in all studies, described as ratio of anus-fourchette distance in girls and anus-scrotum distance in boys to the distance between coccyx and fourchette/scrotum. 18 relevant studies were included describing the values in different ethnic groups and describing its utility. One study was excluded from statistics due to different landmark for measurement. The studies were grouped into 4. Group A:B:C:D comprised of Newborns:Infants:All age groups:Constipated children. We carried out meta-analysis to estimate effect size (mean difference) using STATA software version 16.0. RESULTS: The different ethnic populations in which API were measured, and were Indian (2), Turkish (3), Israel (2), Taiwanese, Thai, Iranian, Spanish, Italian, and Mexican. The API was higher by 0.129 in boys. The mean API in males was 0.53:0.54:0.48:0.52 in Group A:B:C:D with an overall mean (SD) API of 0.51 (0.04). The mean API in females was 0.40:0.40:0.38:0.37 in Group A:B:C:D with an overall mean (SD) API of 0.40(0.03). Two studies were done in mice and showed the relation of API to intrauterine exposure to androgens. In children, API was mostly used to diagnose an anterior ectopic anus and see correlation with constipation. The abnormal values varied from less than 0.30-0.34 in girls and less than 0.41-0.46 in boys. The effect size by regions showed that the estimated effect size for all the regions were within 95% Confidence limits of overall estimate (0.13: 95% CI: 0.13-0.14). Therefore, it can be inferred that there was no significant ethnic variation in the study parameter. The anal position in relation to genitalia was measured in nulliparous women, menopause women, and women with levator deficiency. It was affected in vulvovaginal atrophy. Dichlorodiphenyldichloroethylene exposure during the first trimester of pregnancy was reported to alter the anal position in male infants. CONCLUSION: The anteriorly positioned anus has been associated with constipation. API been measured in various ethnic populations with insignificant variations. The API is significantly (p < 0.05) higher in males. The presence of constipation does not seem to alter API. One should adopt a single method for measurement. API should not be considered at the sole indication for any surgical intervention.

Coccygodynia Due to a Sacrococcygeal Anomaly: A Rare Cause of Constipation.

ABSTRACT: We report a case of an uncommon sacrococcygeal anomaly in a healthy girl initially presenting to the emergency department with coccygodynia and a past history of longstanding constipation. The clinical evolution was satisfactory once the bony anomaly was removed (coccygectomy). This unusual case exemplifies the importance of the medical history and physical examination to make an accurate diagnosis. An inadequate intervention may result in persistent pain, worsening longstanding constipation, and psychosocial and medical consequences.

The Cellular Composition of Bovine Coccygeal Intervertebral Discs: A Comprehensive Single-Cell RNAseq Analysis.

Intervertebral disc (IVD) degeneration and its medical consequences is still one of the leading causes of morbidity worldwide. To support potential regenerative treatments for degenerated IVDs, we sought to deconvolute the cell composition of the nucleus pulposus (NP) and the annulus fibrosus (AF) of bovine intervertebral discs. Bovine calf tails have been extensively used in intervertebral disc research as a readily available source of NP and AF material from healthy and young IVDs. We used single-cell RNA sequencing (scRNAseq) coupled to bulk RNA sequencing (RNAseq) to unravel the cell populations in these two structures and analyze developmental changes across the rostrocaudal axis. By integrating the scRNAseq data with the bulk RNAseq data to stabilize the clustering results of our study, we identified 27 NP structure/tissue specific genes and 24 AF structure/tissue specific genes. From our scRNAseq results, we could deconvolute the heterogeneous cell populations in both the NP and the AF. In the NP, we detected a notochordal-like cell cluster and a progenitor stem cell cluster. In the AF, we detected a stem cell-like cluster, a cluster with a predominantly fibroblast-like phenotype and a potential endothelial progenitor cluster. Taken together, our results illustrate the cell phenotypic complexity of the AF and NP in the young bovine IVDs.

Imaging Coccygeal Trauma and Coccydynia.

The coccygeal region has complex anatomy, much of which may contribute to or be the cause of coccyx region pain (coccydynia). This anatomy is well depicted at imaging, and management is often dictated by what structures are involved. Coccydynia is a common condition that is known to be difficult to evaluate and treat. However, imaging can aid in determining potential causes of pain to help guide management. Commonly, coccydynia (coccygodynia) occurs after trauma and appears with normal imaging features at static neutral radiography, but dynamic imaging with standing and seated lateral radiography may reveal pathologic coccygeal motion that is predictive of pain. In addition, several findings seen at cross-sectional imaging in patients with coccydynia can point to a source of pain that may be subtle and easily overlooked. Radiology can also offer a role in management of coccygeal region pain with image-guided pain management procedures such as ganglion impar block. In addition to mechanical coccyx pain, a host of other conditions involving the sacrococcygeal region may cause coccydynia, which are well depicted at imaging. These include neoplasm, infection, crystal deposition, and cystic formations such as pilonidal cyst. The authors review a variety of coccydynia causes, their respective imaging features, and common management strategies.©RSNA, 2020.

Crossed renal ectopia with fusion in a pelvic inlet area, atypical portal vein and coccygeal deformation in a young female cat.

BACKGROUND: The case report describes a rare congenital anomaly, crossed fused renal ectopia (CFRE), with coexistence of two other abnormalities - atypical portal vein and coccygeal vertebrae malformation in a domestic cat. The concomitance of those 3 congenital defects has not been described previously. CASE PRESENTATION: An 8-month-old female, domestic cat suffering from chronic diarrhea was referred to the diagnostic imaging unit. The patient showed no other clinical symptoms. An abdominal ultrasonographic examination was performed in order to evaluate the condition of abdominal organs, particularly the gastrointestinal tract. The ultrasound examination showed an ectopic duplex kidney at instead of kidneys in their typical location. Computed tomography (CT) with angiographic phase and excretory urography was requested to evaluate the condition of the kidneys and ureters. The final diagnosis was CFRE, atypical portal vein and coccygeal deformation in an asymptomatic cat with no changes in renal function and normal blood parameters. CONCLUSIONS: Crossed fused renal ectopia is a rare congenital anomaly and is easily detectable by an abdominal ultrasonographic examination and CT, which allows more complete assessment of both anatomical relations and secretory function of the kidney. The occurrence of CFRE, abnormal portal vein and spinal malformation in a clinically healthy patient is the evidence that congenital malformations may simultaneously involve various, not directly related structures and systems, without significant influence on blood and urine parameters. Thus the most useful tool in the evaluation of the morphological and functional changes is the diagnostic imaging, especially contrast enhanced CT. Our results show that renal fusions should be considered in the differential diagnosis of caudal abdominal masses.

Pedunculated Perianal Mass in a Neonate: A Rare Case Report.

Congenital perianal pedunculated masses are a rare occurrence in neonates. They are benign in nature and can be excised completely for definitive diagnosis. Here is a report of a rare case of pedunculated perianal mass occurring in a neonate managed successfully.

Classification of fractures of the coccyx from a series of 104 patients.

PURPOSE: To describe a classification of fractures of the coccyx, according to their mechanism. METHODS: A series of 104 consecutive patients with a fracture of the coccyx was studied. The mechanism, level, characteristics of the fracture line and complications were recorded. RESULTS: Three mechanisms are proposed to describe these fractures: flexion, compression and extension (types 1, 2 and 3, respectively). Flexion fractures (38 cases) involved the upper coccyx in 35 cases, and in 3 cases with a perineal trauma, it was the lower coccyx; compression fractures (24 cases) involved the middle coccyx and occurred only when Co2 was square or cuneiform and Co3 was long and straight, hence a nutcracker mechanism; four patients were adolescents with a compression of the sacrum extremity and were labeled adolescent compression fracture of S5 (type 2b); extension fractures (38 cases) were obstetrical and involved the lower coccyx; their key feature was a progressive separation of the fragments with time. Flexion fractures usually healed spontaneously, but an associated intermittent luxation was possible. Nutcracker and obstetrical fractures were instable in their majority. CONCLUSIONS: For the first time, a classification of fractures of the coccyx is presented. Each type exhibits specific features. This should help the clinician in the management of these patients. These slides can be retrieved under Electronic Supplementary Material.

Japanese clinical practice guidelines for sacrococcygeal teratoma, 2017.

BACKGROUND: Sacrococcygeal teratoma (SCT) is the most common extragonadal germ cell tumor in neonates and infants. Although most cases of infantile SCT are benign tumors by nature, some develop into extremely large lesions, leading to massive bleeding, high-output heart failure, disseminated intravascular coagulation, and even fatal outcomes during the neonatal period. In addition, some patients may present with tumor recurrence, malignant transformation, long-term sequelae (including bladder and bowel dysfunction) and lower leg palsy during the long-term follow up. SCT, however, is very rare, and there are few opportunities to encounter this disease, therefore general physicians without expert credentials currently lack information relevant to clinical practice. For this reason, the research project committee has compiled guidelines concerning SCT. METHODS: The purpose of these guidelines was to share information concerning the treatment and follow up of infantile SCT. The guidelines were developed using the methodologies in the Medical Information Network Distribution System. A comprehensive search of the English- and Japanese-language articles in PubMed and Ichu-Shi Web identified only case reports or case series, and the recommendations were developed through a process of informal consensus. RESULTS: The clinical questions addressed the risk factors, the efficacy of cesarean section, the initial devascularization of tumor feeding vessels, interventional radiology, recommended clinical studies for follow up and possible long-term complications. CONCLUSIONS: These are the first guidelines for SCT to be established in Japan, and they may have huge clinical value and significance in terms of developing therapeutic strategies and follow up, potentially contributing to the improvement of the prognosis and quality of life of SCT patients.

In-Depth Investigation into the Transient Humidity Response at the Body-Seat Interface on Initial Contact Using a Dual Temperature and Humidity Sensor.

Relative humidity (RH) at the body-seat interface is considered an important factor in both sitting comfort and generation of health concerns such as skin lesions. Technical difficulties appear to have limited research aimed at the detailed and simultaneous exploration of RH and temperature changes at the body-seat interface; using RH sensors without the capability to record temperature where RH is recorded. To explore the causes of a spike in RH consistently produced on first contact between body and seat surface, we report data from the first use of dual temperature and RH (HTU21D) sensors in this interface. Following evaluation of sensor performance, the effect of local thermal changes on RH was investigated. The expected strong negative correlation between temperature and RH (R² = -0.94) supported the importance of considering both parameters when studying impact of sitting on skin health. The influence of sensor movement speed (higher velocity approach: 0.32 cm/s ± 0.01 cm/s; lower velocity approach: 0.17 cm/s ± 0.01 cm/s) into a static RH region associated with a higher local temperature were compared with data gathered by altering the rate of a person sitting. In all cases, the faster sitting down (or equivalent) generated larger RH outcomes: e.g., in human sitting 53.7% ± 3.3% RH (left mid-thigh), 56.4% ± 5.1% RH (right mid-thigh) and 53.2% ± 2.7% RH (Coccyx). Differences in size of RH change were seen across the measurement locations used to study the body-seat interface. The initial sitting contact induces a transient RH response (duration ≤ 40 s) that does not accurately reflect the microenvironment at the body-seat interface. It is likely that any movement during sitting would result in similar artefact formation. As a result, caution should be taken when investigating RH performance at any enclosed interface when the surfaces may have different temperatures and movement may occur.