A Systematic Literature Review of Peripheral Nerve Stimulation Therapies for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of peripheral nerve stimulation (PNS) for pain. DESIGN: Grade the evidence for PNS. METHODS: An international interdisciplinary work group conducted a literature search for PNS. Abstracts were reviewed to select studies for grading. Inclusion/exclusion criteria included prospective randomized controlled trials (RCTs) with meaningful clinical outcomes that were not part of a larger or previously reported group. Excluded studies were retrospective, had less than two months of follow-up, or existed only as abstracts. Full studies were graded by two independent reviewers using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: Peripheral nerve stimulation was studied in 14 RCTs for a variety of painful conditions (headache, shoulder, pelvic, back, extremity, and trunk pain). Moderate to strong evidence supported the use of PNS to treat pain. CONCLUSION: Peripheral nerve stimulation has moderate/strong evidence. Additional prospective trials could further refine appropriate populations and pain diagnoses.

A Systematic Literature Review of Spine Neurostimulation Therapies for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of spinal cord stimulation (SCS) for pain. DESIGN: Grade the evidence for SCS. METHODS: An international, interdisciplinary work group conducted literature searches, reviewed abstracts, and selected studies for grading. Inclusion/exclusion criteria included randomized controlled trials (RCTs) of patients with intractable pain of greater than one year's duration. Full studies were graded by two independent reviewers. Excluded studies were retrospective, had small numbers of subjects, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: SCS has Level 1 evidence (strong) for axial back/lumbar radiculopathy or neuralgia (five high-quality RCTs) and complex regional pain syndrome (one high-quality RCT). CONCLUSIONS: High-level evidence supports SCS for treating chronic pain and complex regional pain syndrome. For patients with failed back surgery syndrome, SCS was more effective than reoperation or medical management. New stimulation waveforms and frequencies may provide a greater likelihood of pain relief compared with conventional SCS for patients with axial back pain, with or without radicular pain.

Intramedullary fixation of distal fibular fractures: a systematic review of clinical and functional outcomes.

BACKGROUND: Ankle fractures are extremely common and represent nearly one quarter of all lower-limb fractures. In the majority of patients, fractures involve the distal fibula. The current standard in treating unstable fractures is through open reduction and internal fixation (ORIF) with plates and screws. Due to concerns with potentially devastating wound complications, minimally invasive strategies such as intramedullary fixation have been introduced. This systematic review was performed to evaluate the clinical and functional outcomes of intramedullary fixation of distal fibular fractures using either compression screws or nails. MATERIALS AND METHODS: Numerous databases (MEDLINE, PubMed, Embase, Google Scholar) were searched, 17 studies consisting of 1,008 patients with distal fibular fractures treated with intramedullary fixation were found. RESULTS: Mean rate of union was 98.5 %, with functional outcome reported as being good or excellent in up to 91.3 % of patients. Regarding unlocked intramedullary nailing, the mean rate of union was 100 %, with up to 92 % of patients reporting good or excellent functional outcomes. Considering locked intramedullary nailing, the mean rate of union was 98 %, with the majority of patients reporting good or excellent functional outcomes. The mean complication rate across studies was 10.3 %, with issues such as implant-related problems requiring metalwork removal, fibular shortening and metalwork failure predominating. CONCLUSION: Overall, intramedullary fixation of unstable distal fibular fractures can give excellent results that are comparable with modern plating techniques. However, as yet, there is unconvincing evidence that it is superior to standard techniques with regards to clinical and functional outcome. LEVEL OF EVIDENCE: Level IV evidence.

Cemented femoral stem design and postoperative periprosthetic fracture risk following total hip arthroplasty.

Polished taper-slip (PTS) cemented stems have an excellent clinical track record and are the most common stem type used in primary total hip arthroplasty (THA) in the UK. Due to low rates of aseptic loosening, they have largely replaced more traditional composite beam (CB) cemented stems. However, there is now emerging evidence from multiple joint registries that PTS stems are associated with higher rates of postoperative periprosthetic femoral fracture (PFF) compared to their CB stem counterparts. The risk of both intraoperative and postoperative PFF remains greater with uncemented stems compared to either of these cemented stem subtypes. PFF continues to be a devastating complication following primary THA and is associated with high complication and mortality rates. Recent efforts have focused on identifying implant-related risk factors for PFF in order to guide preventative strategies, and therefore the purpose of this article is to present the current evidence on the effect of cemented femoral stem design on the risk of PFF.

Dual-Mobility Acetabular Components in Primary Total Hip Arthroplasty Do Not Increase the Risk of Complication Compared to Conventional Articulations: A Matched Cohort Comparative Analysis.

Background: A recent National Joint Registry report suggests a higher local complication risk for dual-mobility (DM) total hip arthroplasty (THA) compared to conventional articulation THA. This report may be subject to data heterogeneity with multiple confounders. Controlling for these factors by matching demographic characteristics may give different results. We aim to compare 2-year local complication rates between matched DM and conventional THAs in primary hip osteoarthritis. Methods: Data were collected for consecutive primary THAs undertaken via a posterior approach. The conventional articulation and DM cohorts were matched 3:1 for age, gender, American Society of Anesthesiology grade, body mass index, and operative time using a propensity score and nearest neighbor matching method. Outcome measures were 2-year local complication rates, reoperation rates, systemic complication rates, and mortality rates. Demographic and outcome data were compared, and cumulative survival rates (%) were assessed using Kaplan-Meier methodology with a 2-year local complication as the endpoint. Statistical significance was set at P < .05. Results: Four hundred twelve THAs were included: 309 conventional and 103 DM articulations. There were no statistically significant differences between DM and conventional articulation THAs for local complications (7 [6.8%] vs 23 [7.4%], P = .820), reoperations (3 [2.9%] vs 4 [1.3%], P = .374), systemic complications (3 [2.9%] vs 4 [1.3%], P = .374), or 90-day mortality (1 [1%] vs 2 [0.6%], P = 1.000). Kaplan-Meier survival analysis demonstrated similar 2-year survival rates for conventional THAs compared to DM THAs (93.3% [standard error, 0.014] vs 91.9% [standard error, 0.031], P = .906). Conclusions: This matched study shows that there is no difference in local complication rates between DM and conventional THA articulations.

Risk factors for periprosthetic femoral fracture risk around a cemented polished taper-slip stem using an osteoporotic composite bone model.

This biomechanical study aimed to determine if variations in stem material, stem geometry, stem offset and cement viscosity affect mechanical resistance to postoperative periprosthetic fracture (PFF) after hip arthroplasty with a commonly used cemented polished taper-slip (PTS) stem (CPT, Zimmer Biomet) in a novel osteoporotic composite femoral bone model. Thirty-six osteoporotic composite femoral models were tested using a standardised in-vitro loading technique to simulate a typical PFF. Outcome measures were torque to failure (N), fracture energy (N/m2) and rotation to failure (°). Comparisons were made by stem material (cobalt chrome vs stainless steel), stem geometry (CPT stem vs Exeter stem), stem offset (standard offset vs extra extended offset) and cement viscosity (high viscosity vs low viscosity). Statistical comparisons were carried out with significance set at p < 0.05. All tested samples produced clinically representative fracture patterns with varying degrees of bone and cement comminution. There was no statistically significant difference in torque to failure, fracture energy or rotation to failure between any of the compared variables (all p > 0.05). This is the first biomechanical study on mechanical resistance to PFF using osteoporotic composite bone models. For the CPT stem, it confirms that stem material, stem offset, stem geometry and cement viscosity do not affect mechanical resistance to PFF in an osteoporotic bone model.

Arthrodesis of the hip and conversion to total hip arthroplasty: a systematic review.

A systematic review of the literature was performed in order to evaluate the outcomes following arthrodesis of the hip and subsequent conversion to total hip arthroplasty. Eight studies regarding primary hip arthrodesis evaluating 249 hips revealed variable union rates (37.5%-100%) and patient satisfaction rates (69%-100%). Adjacent joint pain was commonly seen in the lower back (up to 75%) and ipsilateral knee (up to 57%) and complications were reported in 8.4%. Eleven studies regarding conversion arthroplasty evaluating 579 patients revealed inconsistent results regarding relief of pain. Complications were seen in up to 54%, most commonly due to mechanical failure, deep infection and nerve palsy. Whilst hip arthrodesis can provide pain relief and patient satisfaction, conversion arthroplasty is associated with an unacceptably high complication rate.

A national survey of United Kingdom trauma units on the use of pelvic binders.

PURPOSE: Major pelvic injuries resulting from high-energy trauma require emergency hospital treatment, and part of the initial management includes mechanical stabilisation of the pelvis. Controversies include binder position, use in lateral compression injuries and application during radiological assessment. We present the results of a survey of both emergency department and orthopaedic specialties. METHODS: A telephone survey of all 144 trauma units in the UK accepting adult pelvic trauma patients was carried out in July 2012. The duty registrar for the emergency and orthopaedic departments was contacted and asked to complete a questionnaire. RESULTS: A response rate of 100% was achieved. Pelvic binders were available for use in approximately three quarters of the trauma units surveyed. Eight-five emergency department (59%) and 79 orthopaedic (54.9%) registrars had been given training on pelvic binder application. Fifty-six emergency department (38.9%) and 114 orthopaedic (79.1%) registrars identified the level of the greater trochanters as the most suitable position for the binder. Forty-five emergency department (31.3%) and 58 orthopaedic (40.3%) registrars used pelvic binders in suspected lateral compression injuries. One hundred and twenty-six emergency department (87.5%) and 113 orthopaedic (78.5%) registrars would not release the binder during radiological assessment of the pelvis in a haemodynamically stable patient. CONCLUSION: There is great variability in practice amongst trauma units in the UK. Training must be formalised and provided as a mandatory part of departmental induction. The use of standardised treatment algorithms in trauma units and the Advanced Trauma and Life Support (ATLS) framework may help decision making and improve patient survival rates.

The role of the transverse acetabular ligament in total hip arthroplasty.

We performed a systematic literature review to evaluate the role of the transverse acetabular ligament as a reference aid when determining acetabular component anteversion in total hip arthroplasty. We conducted a literature search in the MEDLINE, EMBASE and Pubmed databases using the key words 'transverse acetabular ligament' and 'arthroplasty'. Four studies published between 2006 and 2011, reporting on 1,217 procedures met our inclusion and exclusion criteria and were eligible for final evaluation. Outcome measures were the ability to identify the transverse acetabular ligament, anteversion of the acetabular component and dislocation rate. The methodological quality of the studies was variable and they were not homogenous enough for metaanalysis. We found that there was good evidence for the use of the transverse acetabular ligament in terms of accuracy of acetabular component anteversion. However, the ligament could not be routinely identified intra-operatively and other methods of determining the correct anteversion are recommended in this situation. The dislocation rate using this technique was low but it must be stressed that the cause of postoperative dislocation in total hip arthroplasty is multi-factorial and cannot solely be attributed to acetabular component orientation.

Which Unified Classification System type B periprosthetic fractures around cemented polished tapered stems should not be fixed?

The Unified Classification System (UCS), or Vancouver system, is a validated and widely used classification system to guide the management of periprosthetic femoral fractures. It suggests that well-fixed stems (type B1) can be treated with fixation but that loose stems (types B2 and B3) should be revised. Determining whether a stem is loose can be difficult and some authors have questioned how to apply this classification system to polished taper slip stems which are, by definition, loose within their cement mantle. Recent evidence has challenged the common perception that revision surgery is preferable to fixation surgery for UCS-B periprosthetic fractures around cemented polished taper slip stems. Indications for fixation include an anatomically reducible fracture and cement mantle, a well-fixed femoral bone-cement interface, and a well-functioning acetabular component. However, not all type B fractures can or should be managed with fixation due to the risk of early failure. This annotation details specific fracture patterns that should not be managed with fixation alone.

"Wearable Sensors to Guide Remote Rehabilitation Following Knee Arthroplasty Surgery".

Background: Total knee arthroplasty requires effective rehabilitation to achieve optimal results, but institutions often rely on unsupervised home exercises due to cost constraints. Wearable sensors have become increasingly popular as a potential method of monitoring patients remotely to ensure efficacy and compliance. This review assesses the current evidence for their use in remotely monitored rehabilitation following knee arthroplasty. Methods: A systematic review of the literature from 1st January 2000 to 17th February 2022 was undertaken. Devices were categorised as joint-specific or physical activity sensors. Studies were classified as those providing remotely supervised rehabilitation as an additional or as an alternative intervention. Results: Remotely supervised rehabilitation using wearable sensors demonstrated similar outcomes when provided as an alternative to standard care in most studies. One group found improved outcomes for knee-specific sensors compared with standard care. There were improved physical activity and healthcare resource use outcomes described in the literature where sensors were used in addition to standard care. Discussion: This review found evidence for the use of wearable sensors in remotely supervised rehabilitation following knee arthroplasty surgery. This included methodological heterogeneity, differing definitions of standard care, and variable follow-up periods. Robust randomised control trial data with a longer follow-up period are needed.

A multicentre comparative analysis of fixation versus revision surgery for periprosthetic femoral fractures following total hip arthroplasty with a cemented polished taper-slip femoral component.

AIMS: The aim of this study was to compare open reduction and internal fixation (ORIF) with revision surgery for the surgical management of Unified Classification System (UCS) type B periprosthetic femoral fractures around cemented polished taper-slip femoral components following primary total hip arthroplasty (THA). METHODS: Data were collected for patients admitted to five UK centres. The primary outcome measure was the two-year reoperation rate. Secondary outcomes were time to surgery, transfusion requirements, critical care requirements, length of stay, two-year local complication rates, six-month systemic complication rates, and mortality rates. Comparisons were made by the form of treatment (ORIF vs revision) and UCS type (B1 vs B2/B3). Kaplan-Meier survival analysis was performed with two-year reoperation for any reason as the endpoint. RESULTS: A total of 317 periprosthetic fractures (in 317 patients) with a median follow-up of 3.6 years (interquartile range (IQR) 2.0 to 5.4) were included. The fractures were type B1 in 133 (42.0%), B2 in 170 (53.6%), and B3 in 14 patients (4.4%). ORIF was performed in 167 (52.7%) and revision in 150 patients (47.3%). The two-year reoperation rate (15.3% vs 7.2%; p = 0.021), time to surgery (4.0 days (IQR 2.0 to 7.0) vs 2.0 days (IQR 1.0 to 4.0); p < 0.001), transfusion requirements (55 patients (36.7%) vs 42 patients (25.1%); p = 0.026), critical care requirements (36 patients (24.0%) vs seven patients (4.2%); p < 0.001) and two-year local complication rates (26.7% vs 9.0%; p < 0.001) were significantly higher in the revision group. The two-year rate of survival was significantly higher for ORIF (91.9% (standard error (SE) 0.023%) vs 83.9% (SE 0.031%); p = 0.032) compared with revision. For B1 fractures, the two-year reoperation rate was significantly higher for revision compared with ORIF (29.4% vs 6.0%; p = 0.002) but this was similar for B2 and B3 fractures (9.8% vs 13.5%; p = 0.341). The most common indication for reoperation after revision was dislocation (12 patients; 8.0%). CONCLUSION: Revision surgery has higher reoperation rates, longer surgical waiting times, higher transfusion requirements, and higher critical care requirements than ORIF in the management of periprosthetic fractures around polished taper-slip femoral components after THA. ORIF is a safe option providing anatomical reconstruction is achievable.Cite this article: Bone Joint J 2023;105-B(2):124-134.

Anatomic and biomechanical analysis of the short and long head components of the distal biceps tendon.

HYPOTHESIS: The short head bundle of the distal biceps tendon is more efficient at elbow flexion, and the long head is more efficient at forearm supination. METHODS: The short and long head bundles of the distal biceps tendon were separated to the bicipital tuberosity in 6 cadavers. The area and centroid of each bundle insertion were computed from surface points measured within each footprint. Each bundle was individually loaded. The supination torque and flexion load generated were recorded at 90° of elbow flexion. The slope of the torque generated versus biceps load was used to define the supination moment arm. The ratio of the flexion load generated to biceps load applied was used to define the relative flexion efficiency. RESULTS: The short head insertion was positioned distal and anterior relative to the long head and typically included the apex of the tuberosity. The areas of the long and short heads were 59 ± 15 and 94 ± 44 mm(2) (P = .07), respectively. The long head moment arm was significantly higher in supination. The short head had a significantly higher moment arm in neutral and pronation. The ratio of the flexion load to biceps load was 15% higher for the short head. CONCLUSION: The short and long heads of the biceps have distinct insertions. The short head's insertion allows it to be relatively more efficient at elbow flexion at 90°. In the neutral and pronated forearm, the short head is the relatively more efficient supinator. In the supinated forearm, the long head becomes relatively more efficient at supination.

Erenumab for episodic migraine.

In this review, the authors provide an overview of erenumab, a monoclonal antibody used for the preventative treatment of episodic migraine by targeting the CGRP pathway. Randomized controlled trials have shown that erenumab is associated with a statistically significant decrease in monthly migraine days in patients with episodic migraine at monthly doses of 70 or 140 mg when given for a period of 9-12 weeks. Post hoc analyses have also shown long-term maintenance of efficacy. Clinical trials have found erenumab at doses of both 70 and 140 mg to have a favorable safety profile. Erenumab faces significant limitations because of its high financial cost. Additional long-term real-world data are needed to understand the role of erenumab in the treatment of migraine.

In this review, the authors give an overview of erenumab, an injectable medication used to prevent migraine headaches. Erenumab has been proven to be significantly effective in patients with episodic migraines when used at doses of 70 or 140 mg. Furthermore, studies have shown sustained benefit starting as early as the first week of treatment as well as improvement in patients' quality of life. Erenumab has been found to be as safe as placebo in some studies, but there have been some reports of a link to high blood pressure and constipation. However, because of its high cost, patients still face significant barriers to access to erenumab. Additional long-term real-world data are needed to understand the current role of erenumab in the treatment of migraine.

A systematic review of full endoscopic versus micro-endoscopic or open discectomy for lumbar disc herniation.

Aim: Endoscopic discectomies provide several advantages over other techniques such as traditional open lumbar discectomy (OLD) including possibly decreased complications, shorter hospital stay and an earlier return to work. Methods: An electronic database search including MEDLINE/PubMed, EMBASE, Scopus, Cochrane Database of Systematic Reviews and Cochrane Controlled trials (CENTRAL) were reviewed for randomized controlled trials (RCTs) only. Results: A total of nine RCTs met inclusion criteria. Three showed benefit of endoscopic discectomy over the comparator with regards to pain relief, with the remaining six studies showing no difference in pain relief or function. Conclusion: Based on review of the nine included studies, we can conclude that endoscopic discectomy is as effective as other surgical techniques, and has additional benefits of lower complication rate and superior perioperative parameters.

Lay abstract This systematic review investigates the use of a common surgical procedure, endoscopic discectomy, for the surgical treatment of lumbar disc herniation. It is a type of minimally invasive spine surgery (MISS) procedure, which has been shown to be not only effective in outcomes, but also optimal for peri-operative parameters, such as post-operative hospital stay, time duration of surgery and blood loss during the procedure. We utilized five search databases to collect data on only randomized controlled studies that investigated endoscopic discectomy compared with another surgical technique. Our results include nine randomized controlled trials, three of which showed improvement in pain scores for endoscopic discectomies. Consequently, in combination with the optimal peri-operative measures, it is concluded that endoscopic discectomy is a reasonable procedure to treat lumbar disc herniation surgically.

Steroid in Chronic Subdural Hematoma: An Updated Systematic Review and Meta-Analysis Post DEX-CSDH Trial.

BACKGROUND: Chronic subdural hematoma (CSDH) is a neurologic condition characterized as a hematoma in the subdural space with a period >3 weeks that primarily affects the elderly. Glucocorticoid, especially dexamethasone, either alone or combined with surgery, has been used to manage CSDH. We aimed to perform an updated systematic review and meta-analysis of the literature regarding the role of steroids in CSDH. METHODS: We searched the electronic databases PubMed, PubMed Central, Scopus, and Embase for relevant articles until December 2020. Study characteristics, quality, and end points were extracted, and analysis was performed by RevMan 5.4. RESULTS: The odds for subdural hematoma recurrence were decreased by 61% in the steroid group (odds ratio [OR], 0.39; confidence interval [CI], 0.19-0.79) compared with the control group. There was no significant difference in mortality during the study period (OR, 0.66; CI, 0.20-2.18), modified Rankin Scale score 0-3 (OR, 0.87; CI, 0.31-2.40), and modified Rankin Scale score 4-6 (OR, 1.15; CI, 0.42-3.18) between the 2 groups. However, pooling data from 3 studies showed 2.7 times higher odds of occurring adverse effects in steroid groups using the fixed-effect model (OR, 2.70; CI, 1.71-4.28). The treatment success was similar between the steroid and control groups (OR, 2.39; CI, 0.94-6.04). CONCLUSIONS: Treatment with steroids was associated with a lesser recurrence of CSDH. However, there was no benefit of steroid treatment in CSDH compared with nonsteroid treatment in terms of mortality and treatment success and some but significantly increased risk of adverse events.

Periprosthetic femoral fracture type and location are influenced by the presence of an ipsilateral knee arthroplasty implant: A case-control study of 84 interprosthetic femoral fractures.

BACKGROUND: This multicentre case-control study compares Vancouver Classification System (VCS) grade and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) fracture type in interprosthetic femoral fractures (IPFFs) between primary total hip arthroplasty (THA) and ipsilateral total knee arthroplasty (TKA) to periprosthetic femoral fracture (PFF) without ipsilateral TKA. METHODS: Data were collected following institutional approval. Eighty-four IPFFs were assessed for VCS grade and AO/OTA type. Each IPFF case (84) was matched to five PFF controls (360) by age, gender and stem fixation philosophy (SMD<0.1). VCS grade and AO/OTA type were compared between the IPFF and PFF groups using weighted proportions and medians. RESULTS: Median (IQR) age of IPFF patients was 81.75 (76.57-85.33) years and 61 (72.6%) were female. The commonest VCS grade was B1 (34, 40.5%). The commonest AO/OTA type was spiral (51.8% of VCS B fractures; 50.0% of VCS C fractures). A greater proportion of fractures occurred distal to the stem in IPFF patients versus PFF patients (33.3% versus 18.2%, p = 0.003). VCS grade was significantly different between groups (p = 0.015). For VCS C fractures, twice as many AO/OTA transverse and wedge fractures occurred in the IPFF group compared to the PFF group (25.0% versus 12.6% and 7.1% versus 3.3%, respectively) although the overall difference was not statistically significant (p = 0.407). CONCLUSION: The presence of an ipsilateral TKA affects the location of PFF with more fractures occurring distal to the stem. A greater proportion of bending type fractures occurred when an ipsilateral TKA was present. These unstable fractures often require more complex surgery.

The American Society of Pain and Neuroscience (ASPN) Evidence-Based Clinical Guideline of Interventional Treatments for Low Back Pain.

Introduction: Painful lumbar spinal disorders represent a leading cause of disability in the US and worldwide. Interventional treatments for lumbar disorders are an effective treatment for the pain and disability from low back pain. Although many established and emerging interventional procedures are currently available, there exists a need for a defined guideline for their appropriateness, effectiveness, and safety. Objective: The ASPN Back Guideline was developed to provide clinicians the most comprehensive review of interventional treatments for lower back disorders. Clinicians should utilize the ASPN Back Guideline to evaluate the quality of the literature, safety, and efficacy of interventional treatments for lower back disorders. Methods: The American Society of Pain and Neuroscience (ASPN) identified an educational need for a comprehensive clinical guideline to provide evidence-based recommendations. Experts from the fields of Anesthesiology, Physiatry, Neurology, Neurosurgery, Radiology, and Pain Psychology developed the ASPN Back Guideline. The world literature in English was searched using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Scopus, and meeting abstracts to identify and compile the evidence (per section) for back-related pain. Search words were selected based upon the section represented. Identified peer-reviewed literature was critiqued using United States Preventive Services Task Force (USPSTF) criteria and consensus points are presented. Results: After a comprehensive review and analysis of the available evidence, the ASPN Back Guideline group was able to rate the literature and provide therapy grades to each of the most commonly available interventional treatments for low back pain. Conclusion: The ASPN Back Guideline represents the first comprehensive analysis and grading of the existing and emerging interventional treatments available for low back pain. This will be a living document which will be periodically updated to the current standard of care based on the available evidence within peer-reviewed literature.

Reliability and validity of the Unified Classification System for postoperative periprosthetic femoral fractures around cemented polished taper-slip stems.

AIMS: This aim of this study was to assess the reliability and validity of the Unified Classification System (UCS) for postoperative periprosthetic femoral fractures (PFFs) around cemented polished taper-slip (PTS) stems. METHODS: Radiographs of 71 patients with a PFF admitted consecutively at two centres between 25 February 2012 and 19 May 2020 were collated by an independent investigator. Six observers (three hip consultants and three trainees) were familiarized with the UCS. Each PFF was classified on two separate occasions, with a mean time between assessments of 22.7 days (16 to 29). Interobserver reliability for more than two observers was assessed using percentage agreement and Fleiss' kappa statistic. Intraobserver reliability between two observers was calculated with Cohen kappa statistic. Validity was tested on surgically managed UCS type B PFFs where stem stability was documented in operation notes (n = 50). Validity was assessed using percentage agreement and Cohen kappa statistic between radiological assessment and intraoperative findings. Kappa statistics were interpreted using Landis and Koch criteria. All six observers were blinded to operation notes and postoperative radiographs. RESULTS: Interobserver reliability percentage agreement was 58.5% and the overall kappa value was 0.442 (moderate agreement). Lowest kappa values were seen for type B fractures (0.095 to 0.360). The mean intraobserver reliability kappa value was 0.672 (0.447 to 0.867), indicating substantial agreement. Validity percentage agreement was 65.7% and the mean kappa value was 0.300 (0.160 to 0.4400) indicating only fair agreement. CONCLUSION: This study demonstrates that the UCS is unsatisfactory for the classification of PFFs around PTS stems, and that it has considerably lower reliability and validity than previously described for other stem types. Radiological PTS stem loosening in the presence of PFF is poorly defined and formal intraoperative testing of stem stability is recommended. Cite this article: Bone Joint J 2021;103-B(8):1339-1344.