Aims. The outcome following the development of neurological complications after corrective surgery for scoliosis varies from full recovery to a permanent deficit. This study aimed to assess the prognosis and recovery of major neurological deficits in these patients, and to determine the risk factors for non-recovery, at a minimum follow-up of two years. Methods. A major neurological deficit was identified in 65 of 8,870 patients who underwent corrective surgery for scoliosis, including eight with complete paraplegia and 57 with incomplete paraplegia. There were 23 male and 42 female patients. Their mean age was 25.0 years (SD 16.3). The aetiology of the scoliosis was idiopathic (n = 6), congenital (n = 23), neuromuscular (n = 11), neurofibromatosis type 1 (n = 6), and others (n = 19). Neurological function was determined by the American Spinal Injury Association (ASIA) impairment scale at a mean follow-up of 45.4 months (SD 17.2). the patients were divided into those with recovery and those with no recovery according to the ASIA scale during follow-up. Results. The incidence of major deficit was 0.73%. At six-month follow-up, 39 patients (60%) had complete recovery and ten (15.4%) had incomplete recovery; these percentages improved to 70.8% (46) and 16.9% (11) at follow-up of two years, respectively. Eight patients showed no recovery at the final follow-up. The cause of injury was mechanical in 39 patients and ischaemic in five. For 11 patients with misplaced implants and haematoma formation, nine had complete recovery. Fisher’s exact test showed a significant difference in the aetiology of the scoliosis (p = 0.007) and preoperative deficit (p = 0.016) between the recovery and non-recovery groups. A preoperative deficit was found to be significantly associated with non-recovery (odds ratio 8.5 (95% confidence interval 1.676 to 43.109); p = 0.010) in a multivariate regression model. Conclusion. For patients with scoliosis who develop a major neurological deficit after corrective surgery, recovery (complete and incomplete) can be expected in 87.7%. The first three to six months is the time window for recovery. In patients with misplaced implants and haematoma formation, the prognosis is satisfactory with appropriate early intervention. Patients with a preoperative neurological deficit are at a significant risk of having a permanent deficit. Cite this article: Bone Joint J 2022;104-B(1):103–111

Aims. This study aimed to evaluate the incidence and prognosis of patients with spinal metastasis as the initial manifestation of malignancy (SM-IMM). Patients and Methods. We retrospectively reviewed the electronic medical records of 338 patients who underwent surgical treatment for metastatic spinal disease. The enrolled patients were divided into two groups. The SM-IMM group included patients with no history of malignancy whose site of primary malignancy was diagnosed after the identification of spinal metastasis. The other group included patients with a history of treatment for primary malignancy who then developed spinal metastasis (SM-DTM). The incidence of SM-IMM by site of primary malignancy was calculated. The difference between prognoses after surgical treatment for SM-IMM and SM-DTM was established. Results. The median follow-up period was 11.5 months (interquartile range (IQR) 3.2 to 13.4) after surgical treatment. During the follow-up period, 264 patients died; 74 patients survived. The SM-IMM group consisted of 94 patients (27.8%). The site of primary malignancy in the SM-IMM group was lung in 35/103 patients (34.0%), liver in 8/45 patients (17.8%), kidney in 10/33 patients (30.3%), colorectum in 3/29 patients (10.3%), breast in 3/22 patients (13.6%), prostate in 3/10 patients (30%), thyroid in 4/8 patients (50%), and ‘other’ in 28/88 patients (31.8%). On Kaplan–Meier survival analysis, the SM-IMM group showed a significantly longer survival than the SM-DTM group (p = 0.013). The mean survival time was 23.0 months (95% confidence interval (CI) 15.5 to 30.5) in the SM-IMM group and 15.5 months (95% CI 11.8 to 19.2) in the SM-DTM group. Conclusion. Of the 338 enrolled patients who underwent surgical treatment for spinal metastasis, 94 patients (27.8%) underwent surgical treatment for SM-IMM. The SM-IMM group had an acceptable prognosis with surgical treatment. Cite this article: Bone Joint J 2019;101-B:1379–1384

Seventy children who had suffered from Perthes' disease were reviewed clinically and radiologically three to eight years from the onset of the condition in order to determine retrospectively the most satisfactory method of assessing the prognosis and the correlation between the clinical and radiological result. In younger children the femoral head was more likely to be spherical at the conclusion of the pathological process but not necessarily of normal proportions nor normally covered by the acetabulum. The prognosis was significantly poorer for girls than for boys. Clinical factors were not an aid to prognosis in the individual cases, but overall there was a close correlation between the clinical and the radiological end-results. The most reliable radiological factors indicating the prognosis were the extent of uncovering of the femoral head, the Catterall grouping, the presence of calcification lateral to the outer limit of the acetabulum and lateral displacement of the femoral head, as measured by comparing the head to tear-drop distances on each side

Tennis elbow (lateral epicondylitis or lateral elbow tendinopathy) is a self-limiting condition in most patients. Surgery is often offered to patients who fail to improve with conservative treatment. However, there is no evidence to support the superiority of surgery over continued nonoperative care or no treatment. New evidence also suggests that the prognosis of tennis elbow is not influenced by the duration of symptoms, and that there is a 50% probability of recovery every three to four months. This finding challenges the belief that failed nonoperative care is an indication for surgery. In this annotation, we discuss the clinical and research implications of the benign clinical course of tennis elbow. Cite this article: Bone Joint J 2023;105-B(2):109–111

The clinical results in a series of 131 patients with 134 brachial plexus injuries were analysed to determine the factors affecting prognosis. Isolated injuries to the upper trunk had the best prognosis, but the prognoses of isolated injuries to the cords, upper roots and lower trunk were not as good. Complete injuries of the plexus had the worst prognosis. Pain which persisted for more than six months was a bad prognostic sign for neurological recovery regardless of the location of the lesion. Horner's syndrome was not always accompanied by a bad prognosis. Operation did not affect the prognosis except in open lacerations. A pseudomeningocele detected by myelography usually precluded recovery in the root at the level of the pseudomeningocele

Prediction tools are instruments which are commonly used to estimate the prognosis in oncology and facilitate clinical decision-making in a more personalized manner. Their popularity is shown by the increasing numbers of prediction tools, which have been described in the medical literature. Many of these tools have been shown to be useful in the field of soft-tissue sarcoma of the extremities (eSTS). In this annotation, we aim to provide an overview of the available prediction tools for eSTS, provide an approach for clinicians to evaluate the performance and usefulness of the available tools for their own patients, and discuss their possible applications in the management of patients with an eSTS. Cite this article: Bone Joint J 2022;104-B(9):1011–1016

Injuries to the quadriceps muscle group are common in athletes performing high-speed running and kicking sports. The complex anatomy of the rectus femoris puts it at greatest risk of injury. There is variability in prognosis in the literature, with reinjury rates as high as 67% in the severe graded proximal tear. Studies have highlighted that athletes can reinjure after nonoperative management, and some benefit may be derived from surgical repair to restore function and return to sport (RTS). This injury is potentially career-threatening in the elite-level athlete, and we aim to highlight the key recent literature on interventions to restore strength and function to allow early RTS while reducing the risk of injury recurrence. This article reviews the optimal diagnostic strategies and classification of quadriceps injuries. We highlight the unique anatomy of each injury on MRI and the outcomes of both nonoperative and operative treatment, providing an evidence-based management framework for athletes. Cite this article: Bone Joint J 2023;105-B(12):1244–1251

Aims. Early large treatment effects can arise in small studies, which lessen as more data accumulate. This study aimed to retrospectively examine whether early treatment effects occurred for two multicentre orthopaedic randomized controlled trials (RCTs) and explore biases related to this. Methods. Included RCTs were ProFHER (PROximal Fracture of the Humerus: Evaluation by Randomisation), a two-arm study of surgery versus non-surgical treatment for proximal humerus fractures, and UK FROST (United Kingdom Frozen Shoulder Trial), a three-arm study of two surgical and one non-surgical treatment for frozen shoulder. To determine whether early treatment effects were present, the primary outcome of Oxford Shoulder Score (OSS) was compared on forest plots for: the chief investigator’s (CI) site to the remaining sites, the first five sites opened to the other sites, and patients grouped in quintiles by randomization date. Potential for bias was assessed by comparing mean age and proportion of patients with indicators of poor outcome between included and excluded/non-consenting participants. Results. No bias in treatment effect was observed overall for the CI site, or the first five sites, compared with the remaining sites in either trial. An early treatment effect on the OSS was observed for the first quintile of participants recruited to ProFHER only (clinically relevant difference of seven points). Selection bias for age was observed in the ProFHER trial only, with slightly younger patients being recruited into the study. Both trials showed some selection bias for markers of poor prognosis, although these did not appear to change over time. Conclusion. No bias in treatment effects overall were found at the CI or early sites set-up. An early treatment effect was found in one of the two trials, which was likely a chance effect as this did not continue during the study. Selection bias was observed in both RCTs, however this was minimal and did not impact on outcome. Cite this article: Bone Jt Open 2023;4(2):96–103

Aims. Radiotherapy is a well-known local treatment for spinal metastases. However, in the presence of postoperative systemic therapy, the efficacy of radiotherapy on local control (LC) and overall survival (OS) in patients with spinal metastases remains unknown. This study aimed to evaluate the clinical outcomes of post-surgical radiotherapy for spinal metastatic non-small-cell lung cancer (NSCLC) patients, and to identify factors correlated with LC and OS. Methods. A retrospective, single-centre review was conducted of patients with spinal metastases from NSCLC who underwent surgery followed by systemic therapy at our institution from January 2018 to September 2022. Kaplan-Meier analysis and log-rank tests were used to compare the LC and OS between groups. Associated factors for LC and OS were assessed using Cox proportional hazards regression analysis. Results. Overall, 123 patients with 127 spinal metastases from NSCLC who underwent decompression surgery followed by postoperative systemic therapy were included. A total of 43 lesions were treated with stereotactic body radiotherapy (SBRT) after surgery and 84 lesions were not. Survival rate at one, two, and three years was 83.4%, 58.9%, and 48.2%, respectively, and LC rate was 87.8%, 78.8%, and 78.8%, respectively. Histological type was the only significant associated factor for both LC (p = 0.007) and OS (p < 0.001). Treatment with targeted therapy was significantly associated with longer survival (p = 0.039). The risk factors associated with worse survival were abnormal laboratory data (p = 0.021), lesions located in the thoracic spine (p = 0.047), and lumbar spine (p = 0.044). This study also revealed that postoperative radiotherapy had little effect in improving OS or LC. Conclusion. Tumour histological type was significantly associated with the prognosis in spinal NSCLC metastasis patients. In the presence of post-surgical systemic therapy, radiotherapy appeared to be less effective in improving LC, OS, or quality of life in spinal NSCLC metastasis patients. Cite this article: Bone Jt Open 2024;5(4):350–360

Aims. The localization of necrotic areas has been reported to impact the prognosis and treatment strategy for osteonecrosis of the femoral head (ONFH). Anteroposterior localization of the necrotic area after a femoral neck fracture (FNF) has not been properly investigated. We hypothesize that the change of the weight loading direction on the femoral head due to residual posterior tilt caused by malunited FNF may affect the location of ONFH. We investigate the relationship between the posterior tilt angle (PTA) and anteroposterior localization of osteonecrosis using lateral hip radiographs. Methods. Patients aged younger than 55 years diagnosed with ONFH after FNF were retrospectively reviewed. Overall, 65 hips (38 males and 27 females; mean age 32.6 years (SD 12.2)) met the inclusion criteria. Patients with stage 1 or 4 ONFH, as per the Association Research Circulation Osseous classification, were excluded. The ratios of anterior and posterior viable areas and necrotic areas of the femoral head to the articular surface were calculated by setting the femoral head centre as the reference point. The PTA was measured using Palm’s method. The association between the PTA and viable or necrotic areas of the femoral head was assessed using Spearman’s rank correlation analysis (median PTA 6.0° (interquartile range 3 to 11.5)). Results. We identified a negative correlation between PTA and anterior viable areas (rho −0.477; p = 0.001), and no correlation between PTA and necrotic (rho 0.229; p = 0.067) or posterior viable areas (rho 0.204; p = 0.132). Conclusion. Our results suggest that residual posterior tilt after FNF could affect the anteroposterior localization of necrosis. Cite this article: Bone Jt Open 2024;5(5):394–400

Aims. The aim of this study is to determine the predictors of overall survival (OS) and predictive factors of poor prognosis of conventional high-grade osteosarcoma of the limbs in a single-centre in South Africa. Methods. We performed a retrospective cross-sectional analysis to identify the prognostic factors that predict the OS of patients with histologically confirmed high-grade conventional osteosarcoma of the limbs over ten years. We employed the Cox proportional regression model and the Kaplan-Meier method for statistical analysis. Results. This study comprised 77 patients at a three-year minimum follow-up. The predictors of poor OS were: the median age of ≤ 19 years (hazard ratio (HR) 0.96; 95% confidence interval (CI) 0.92 to 0.99; p = 0.021); median duration of symptoms ≥ five months (HR 0.91; 95% CI 0.83 to 0.99; p < 0.037); metastasis at diagnosis (i.e. Enneking stage III) (HR 3.33; 95% CI 1.81 to 6.00; p < 0.001); increased alkaline phosphatase (HR 3.28; 95% CI 1.33 to 8.11; p < 0.010); palliative treatment (HR 7.27; 95% CI 2.69 to 19.70); p < 0.001); and amputation (HR 3.71; 95% CI 1.12 to 12.25; p < 0.032). In contrast, definitive surgery (HR 0.11; 95% CI 0.03 to 0.38; p < 0.001) and curative treatment (HR 0.18; 95% CI 0.10 to 0.33; p < 0.001) were a protective factor. The Kaplan-Meier median survival time was 24 months, with OS of 57.1% at the three years. The projected five-year event-free survival was 10.3% and OS of 29.8% (HR 0.76; 95% CI 0.52 to 1.12; p = 0.128). Conclusion. In this series of high-grade conventional osteosarcoma of the appendicular skeleton from South Africa, 58.4% (n = 45) had detectable metastases at presentation; hence, an impoverished OS of five years was 29.8%. Large-scale future research is needed to validate our results. Cite this article: Bone Jt Open 2024;5(3):210–217

Aims. The aim of this study was to report the long-term prognosis of patients with multiple Langerhans cell histiocytosis (LCH) involving the spine, and to analyze the risk factors for progression-free survival (PFS). Methods. We included 28 patients with multiple LCH involving the spine treated between January 2009 and August 2021. Kaplan-Meier methods were applied to estimate overall survival (OS) and PFS. Univariate Cox regression analysis was used to identify variables associated with PFS. Results. Patients with multiple LCH involving the spine accounted for 15.4% (28/182 cases) of all cases of spinal LCH: their lesions primarily involved the thoracic and lumbar spines. The most common symptom was pain, followed by neurological dysfunction. All patients presented with osteolytic bone destruction, and 23 cases were accompanied by a paravertebral soft-tissue mass. The incidence of vertebra plana was low, whereas the oversleeve-like sign was a more common finding. The alkaline phosphatase was significantly higher in patients with single-system multifocal bone LCH than in patients with multisystem LCH. At final follow-up, one patient had been lost to follow-up, two patients had died, three patients had local recurrence, six patients had distant involvement, and 17 patients were alive with disease. The median PFS and OS were 50.5 months (interquartile range (IQR) 23.5 to 63.1) and 60.5 months (IQR 38.0 to 73.3), respectively. Stage (hazard ratio (HR) 4.324; p < 0.001) and chemotherapy (HR 0.203; p < 0.001) were prognostic factors for PFS. Conclusion. Pain is primarily due to segmental instability of the spine from its destruction by LCH. Chemotherapy can significantly improve PFS, and radiotherapy has achieved good results in local control. The LCH lesions in some patients will continue to progress. It may initially appear as an isolated or single-system LCH, but will gradually involve multiple sites or systems. Therefore, long-term follow-up and timely intervention are important for patients with spinal LCH. Cite this article: Bone Joint J 2023;105-B(6):679–687

1. Three hundred and twenty cases of tuberculosis of the hip joint have been analysed and the late results assessed three or more years after discharge from hospital. 2. The primary bone focus involved the acetabulum alone in 39·3 per cent; the acetabulum and femoral head in 34·1 per cent; the head of femur alone in 19·2 per cent, and the femoral neck alone in 7·4 per cent. In 101 cases widespread destruction of the joint had taken place by the time the patient first came under observation. 3. Premature epiphysial fusion round the knee joint of the affected side occurred in 23 per cent of all patients under the age of fifteen years. 4. When hip disease was complicated by multiple foci of active tuberculosis or by secondarily infected abscesses and sinuses, the prognosis was seriously worsened. 5. Significant late deformity occurred in 38·3 per cent of patients discharged with "sound" fibrous ankylosis, and in 60·5 per cent of those with an unstable fibrous ankylosis. 6. Of 187 patients observed for more than three years after discharge from hospital 174 returned to full activity, seven were partly incapacitated and six were totally incapacitated. 7. Analysis of the late results suggests that the prognosis is best when an adequate period of conservative treatment is followed by some form of arthrodesis operation

Aims. Given the possible radiation damage and inaccuracy of radiological investigations, particularly in children, ultrasound and superb microvascular imaging (SMI) may offer alternative methods of evaluating new bone formation when limb lengthening is undertaken in paediatric patients. The aim of this study was to assess the use of ultrasound combined with SMI in monitoring new bone formation during limb lengthening in children. Methods. In this retrospective cohort study, ultrasound and radiograph examinations were performed every two weeks in 30 paediatric patients undergoing limb lengthening. Ultrasound was used to monitor new bone formation. The number of vertical vessels and the blood flow resistance index were compared with those from plain radiographs. Results. We categorized the new bone formation into three stages: stage I (early lengthening), in which there was no obvious callus formation on radiographs and ultrasound; stage II (lengthening), in which radiographs showed low-density callus formation with uneven distribution and three sub-stages could be identified on ultrasound: in Ia punctate callus was visible; in IIb there was linear callus formation which was not yet connected and in IIc there was continuous linear callus. In stage III (healing), the bone ends had united, the periosteum was intact, and the callus had disappeared, as confirmed on radiographs, indicating healed bone. A progressive increase in the number of vertical vessels was noted in the early stages, peaking during stages IIb and IIc, followed by a gradual decline (p < 0.001). Delayed healing involved patients with a prolonged stage IIa or those who regressed to stage IIa from stages IIb or IIc during lengthening. Conclusion. We found that the formation of new bone in paediatric patients undergoing limb lengthening could be reliably evaluated using ultrasound when combined with the radiological findings. This combination enabled an improved assessment of the prognosis, and adjustments to the lengthening protocol. While SMI offered additional insights into angiogenesis within the new bone, its role primarily contributed to the understanding of the microvascular environment rather than directly informing adjustments of treatment. Cite this article: Bone Joint J 2024;106-B(7):751–758

Aims. Venous tumour thrombus (VTT) is a rare finding in osteosarcoma. Despite the high rate of VTT in osteosarcoma of the pelvis, there are very few descriptions of VTT associated with extrapelvic primary osteosarcoma. We therefore sought to describe the prevalence and presenting features of VTT in osteosarcoma of both the pelvis and the limbs. Methods. Records from a single institution were retrospectively reviewed for 308 patients with osteosarcoma of the pelvis or limb treated between January 2000 and December 2022. Primary lesions were located in an upper limb (n = 40), lower limb (n = 198), or pelvis (n = 70). Preoperative imaging and operative reports were reviewed to identify patients with thrombi in proximity to their primary lesion. Imaging and histopathology were used to determine presence of tumour within the thrombus. Results. Tumours abutted the blood vessels in 131 patients (43%) and encased the vessels in 30 (10%). Any form of venous thrombus was identified in 31 patients (10%). Overall, 21 of these thrombi were determined to be involved with the tumour based on imaging (n = 9) or histopathology (n = 12). The rate of VTT was 25% for pelvic osteosarcoma and 1.7% for limb osteosarcoma. The most common imaging features associated with histopathologically proven VTT were enhancement with contrast (n = 12; 100%), venous enlargement (n = 10; 83%), vessel encasement (n = 8; 66%), and visible intraluminal osteoid matrix (n = 6; 50%). Disease-specific survival (DSS) for patients with VTT was 95% at 12 months (95% CI 0.87 to 1.00), 50% at three years (95% CI 0.31 to 0.80), and 31% at five years (95% CI 0.14 to 0.71). VTT was associated with worse DSS (hazard ratio 2.3 (95% CI 1.11 to 4.84). Conclusion. VTT is rare with osteosarcoma and occurs more commonly in the pelvis than the limbs. Imaging features suggestive of VTT include enhancement with contrast, venous dilation, and vessel encasement. VTT portends a worse prognosis for patients with osteosarcoma, with a similar survivability to metastatic disease. Cite this article: Bone Joint J 2024;106-B(8):865–870

Aims. Delirium is associated with adverse outcomes following hip fracture, but the prevalence and significance of delirium for the prognosis and ongoing rehabilitation needs of patients admitted from home is less well studied. Here, we analyzed relationships between delirium in patients admitted from home with 1) mortality; 2) total length of hospital stay; 3) need for post-acute inpatient rehabilitation; and 4) hospital readmission within 180 days. Methods. This observational study used routine clinical data in a consecutive sample of hip fracture patients aged ≥ 50 years admitted to a single large trauma centre during the COVID-19 pandemic between 1 March 2020 and 30 November 2021. Delirium was prospectively assessed as part of routine care by the 4 A’s Test (4AT), with most assessments performed in the emergency department. Associations were determined using logistic regression adjusted for age, sex, Scottish Index of Multiple Deprivation quintile, COVID-19 infection within 30 days, and American Society of Anesthesiologists grade. Results. A total of 1,821 patients were admitted, with 1,383 (mean age 79.5 years; 72.1% female) directly from home. Overall, 87 patients (4.8%) were excluded due to missing 4AT scores. Delirium prevalence in the whole cohort was 26.5% (460/1,734): 14.1% (189/1,340) in the subgroup of patients admitted from home, and 68.8% (271/394) in the remaining patients (comprising care home residents and inpatients when fracture occurred). In patients admitted from home, delirium was associated with a 20-day longer total length of stay (p < 0.001). In multivariable analyses, delirium was associated with higher mortality at 180 days (odds ratio (OR) 1.69 (95% confidence interval (CI) 1.13 to 2.54); p = 0.013), requirement for post-acute inpatient rehabilitation (OR 2.80 (95% CI 1.97 to 3.96); p < 0.001), and readmission to hospital within 180 days (OR 1.79 (95% CI 1.02 to 3.15); p = 0.041). Conclusion. Delirium affects one in seven patients with a hip fracture admitted directly from home, and is associated with adverse outcomes in these patients. Delirium assessment and effective management should be a mandatory part of standard hip fracture care. Cite this article: Bone Jt Open 2023;4(6):447–456

Aims. Patients with cauda equina syndrome (CES) require emergency imaging and surgical decompression. The severity and type of symptoms may influence the timing of imaging and surgery, and help predict the patient’s prognosis. Categories of CES attempt to group patients for management and prognostication purposes. We aimed in this study to assess the inter-rater reliability of dividing patients with CES into categories to assess whether they can be reliably applied in clinical practice and in research. Methods. A literature review was undertaken to identify published descriptions of categories of CES. A total of 100 real anonymized clinical vignettes of patients diagnosed with CES from the Understanding Cauda Equina Syndrome (UCES) study were reviewed by consultant spinal surgeons, neurosurgical registrars, and medical students. All were provided with published category definitions and asked to decide whether each patient had ‘suspected CES’; ‘early CES’; ‘incomplete CES’; or ‘CES with urinary retention’. Inter-rater agreement was assessed for all categories, for all raters, and for each group of raters using Fleiss’s kappa. Results. Each of the 100 participants were rated by four medical students, five neurosurgical registrars, and four consultant spinal surgeons. No groups achieved reasonable inter-rater agreement for any of the categories. CES with retention versus all other categories had the highest inter-rater agreement (kappa 0.34 (95% confidence interval 0.27 to 0.31); minimal agreement). There was no improvement in inter-rater agreement with clinical experience. Across all categories, registrars agreed with each other most often (kappa 0.41), followed by medical students (kappa 0.39). Consultant spinal surgeons had the lowest inter-rater agreement (kappa 0.17). Conclusion. Inter-rater agreement for categorizing CES is low among clinicians who regularly manage these patients. CES categories should be used with caution in clinical practice and research studies, as groups may be heterogenous and not comparable. Cite this article: Bone Joint J 2023;105-B(9):1007–1012

Aims. To explore the effect of different durations of antibiotics after stage II reimplantation on the prognosis of two-stage revision for chronic periprosthetic joint infection (PJI). Methods. This study involved a retrospective collection of patients who underwent two-stage revision for chronic PJI and continued to use extended antibiotic prophylaxis in two regional medical centres from January 2010 to June 2018. The patients were divided into a short (≤ one month) or a long (> one month) course of treatment based on the duration of antibiotics following stage II reimplantation. The difference in the infection control rate between the two groups was compared, and prognostic factors for recurrence were analyzed. Results. A total of 105 patients with chronic PJI were enrolled: 64 patients in the short course group and 41 patients in the long course group. For 99 of the patients, the infection was under control during a follow-up period of at least 24 months after two-stage revision. For the short course group, the mean duration of antibiotic prophylaxis after stage II reimplantation was 20.17 days (SD 5.30) and the infection control rate was 95.3%; for the long course group these were 45.02 days (SD 15.03) and 92.7%, respectively. There was no significant difference in infection control rates between the two groups (p = 0.676). Cox regression analysis found that methicillin-resistant staphylococcus infection (p = 0.015) was an independent prognostic factor for recurrence. Conclusion. After stage II reimplantation surgery of two-stage revision for chronic PJI, extended antibiotic prophylaxis for less than one month can achieve good infection control rate. Cite this article: Bone Joint Res 2021;10(12):790–796

Injury of the neck may result when a motor vehicle is run into from behind; such injury is frequently the cause of prolonged disability and litigation. We report a series of 61 patients with these injuries. A classification, based upon the presenting symptoms and physical signs has been evolved. This classification is shown to be a reliable basis for formulating a prognosis. Factors which adversely affect prognosis include the presence of objective neurological signs, stiffness of the neck, muscle spasm, and pre-existing degenerative spondylosis

1. Forty-five cases of zoster paralysis, not involving the cranial nerves, are detailed. These include eighteen cases not previously published. Of these eighteen patients, one-third were referred for an orthopaedic opinion. 2. Complete or almost full recovery occurred within a year in two-thirds of the patients. Permanent paralysis occurred in one-sixth of the patients studied. 3. Muscles that failed to recover were mainly or wholly supplied from single segments of the spinal cord; so the prognosis must be guarded in those cases in which such muscles are completely paralysed. 4. Various phenomena occurring in zoster paralysis are discussed