Tibial insert design significantly alters knee kinematics using a single cruciate-retaining total knee implant.

Aims: Patient dissatisfaction is not uncommon following primary total knee arthroplasty. One proposed method to alleviate this is by improving knee kinematics. Therefore, we aimed to answer the following research question: are there significant differences in knee kinematics based on the design of the tibial insert (cruciate-retaining (CR), ultra-congruent (UC), or medial congruent (MC))? Methods: Overall, 15 cadaveric knee joints were examined with a CR implant with three different tibial inserts (CR, UC, and MC) using an established knee joint simulator. The effects on coronal alignment, medial and lateral femoral roll back, femorotibial rotation, bony rotations (femur, tibia, and patella), and patellofemoral length ratios were determined. Results: No statistically significant differences were found regarding coronal alignment (p = 0.087 to p = 0.832). The medial congruent insert demonstrated restricted femoral roll back (mean medial 37.57 mm; lateral 36.34 mm), while the CR insert demonstrated the greatest roll back (medial 42.21 mm; lateral 37.88 mm; p < 0.001, respectively). Femorotibial rotation was greatest with the CR insert with 2.45° (SD 4.75°), then the UC insert with 1.31° (SD 4.15°; p < 0.001), and lowest with the medial congruent insert with 0.8° (SD 4.24°; p < 0.001). The most pronounced patella shift, but lowest patellar rotation, was noted with the CR insert. Conclusion: The MC insert demonstrated the highest level of constraint of these inserts. Femoral roll back, femorotibial rotation, and single bony rotations were lowest with the MC insert. The patella showed less shifting with the MC insert, but there was significantly increased rotation. While the medial congruent insert was found to have highest constraint, it remains uncertain if this implant recreates native knee kinematics or if this will result in improved patient satisfaction.

Two Cases of Sporadic Amyotrophic Lateral Sclerosis With Contrasting Clinical Phenotypes: Genetic Insights.

Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disease that affects individuals of diverse racial and ethnic backgrounds. There is currently no cure for ALS, and the number of efficient disease-modifying drugs for ALS is limited to a few, despite the large number of clinical trials conducted in recent years. The latter could be attributed to the significant heterogeneity of ALS clinical phenotypes even in their familial forms. To address this issue, we conducted postmortem genetic screening of two female patients with sporadic ALS (sALS) and contrasting clinical phenotypes. The results demonstrated that despite their contrasting clinical phenotypes, both patients had rare pathologic/deleterious mutations in five genes: ACSM5, BBS12, HLA-DQB1, MUC20, and OBSCN, with mutations in three of those genes being identical: BBS12, HLA-DQB1, and MUC20. Additional groups of mutated genes linked to ALS, other neurologic disorders, and ALS-related pathologies were also identified. These data are consistent with a hypothesis that an individual could be primed for ALS via mutations in a specific set of genes not directly linked to ALS. The disease could be initiated by a concerted action of several mutated genes linked to ALS and the disease's clinical phenotype will evolve further through accessory gene mutations associated with other neurological disorders and ALS-related pathologies.

Not so Fast: Extended Oral Antibiotic Prophylaxis Does Not Reduce 90-Day Infection Rate Following Joint Arthroplasty.

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication following both total hip (THA) and knee (TKA) arthroplasty. Extended oral antibiotic (EOA) prophylaxis has been reported to reduce PJI following TJA in high-risk patients. The purpose of this study was to determine if EOA reduces PJI in all-comers and high-risk THA and TKA populations. METHODS: This is a retrospective cohort study, including 4,576 patients undergoing primary THA or TKA at a single institution from 2018 to 2022. Beginning in 2020, EOA prophylaxis was administered for 10 days following THA or TKA at our institution. Patients were separated into 2 cohorts (1,769 EOA, 2,807 no EOA) based on whether they received postoperative EOA. The 90-day and 1-year outcomes, with a focus on PJI, were then compared between groups. A subgroup analysis of high-risk patients was also performed. RESULTS: There was no difference in 90-day PJI rates between cohorts (EOA 1 versus no EOA 0.8%; P = .6). The difference in the rate of PJI remained insignificant at 1 year (EOA 1 versus no EOA 1%; P = .9). Similarly, our subgroup analysis of high-risk patients demonstrated no difference in postoperative PJI between EOA (n = 254) and no EOA (n = 396) (0.8 versus 2.3%, respectively; P = .2). Reassuringly, we also found no differences in the incidence of Clostridium difficile infection (EOA 0.1 versus no EOA 0.1%; P > .9) or in antibiotic resistance among those who developed PJI within 90 days (EOA 59 versus no EOA 83%; P = .2). CONCLUSIONS: With the numbers available for analysis, EOA prophylaxis was not associated with PJI risk reduction following primary TJA when universally deployed. Furthermore, among high-risk patients, there was no statistically significant difference. While we did not identify increased antibiotic resistance or Clostridium difficile infection, we cannot recommend wide-spread adoption of EOA prophylaxis, and clarification regarding the role of EOA, even in high-risk patients, is needed.

A Rare Case of Penoscrotal Webbing and Extensive Hernias: An Anatomical Report With Genetic Insights.

During a routine anatomical dissection of an 81-year-old male cadaver received through the Gift Body Program of Saint Louis University School of Medicine (SLU SOM), a massive bulging in the abdominal area was observed that was consistent with numerous hernia repairs noted in the donor's self-reported medical history. Gross anatomical dissection of the cadaveric body revealed extensive herniation of portions of the small intestine and peritoneal sac along the costal margin and extending to the left aspect of the abdomen. Additionally, an uncircumcised phallus was buried within the suprapubic fat pad and demonstrated simple, grade III penoscrotal webbing (PSW), creating an impression of micropenis presence. To gain additional insights into the current case, analysis of the coding regions (exomes) of DNA procured from the body for putative genetic variants was performed using next-generation sequencing (NGS) technology. This analysis revealed 110 rare (minor allele frequency (MAF) ≤ 0.01), pathologic/deleterious genetic mutations. The most relevant variants to this case were the ones associated with male sexual development, BMP1 and BMP4; connective tissue development, COL3A1 and COL5A3; cilia morphogenesis and function, DNAH5 and MAPK15; as well as hormonal homeostasis, ESR1. Direct involvement of BMP1 both in male sexual development and hernia genesis makes it a strong candidate for linking the two pathologies, PSW and multiple hernias, observed in the present case. Yet the presence of a group of mutated genes linked to myopathies (ITGA7, NRAP, POLM, SCN5A, XIRP2) and muscular dystrophy (ITGA7) raises a question about the involvement of these muscular pathologies in hernia genesis and unsuccessful hernia repairs associated with the current case.

Preoperative Patient Reported Outcomes Predict Postoperative Clinical Outcomes Following Rotator Cuff Repair.

PURPOSE: The purpose of this study was to determine whether preoperative patient-reported outcomes (PROs) predict postoperative PROs and satisfaction following rotator cuff repair. METHODS: We retrospectively identified patients who underwent a primary rotator cuff repair at a single institution. A receiver operating characteristics (ROC) analysis was used to reach a preoperative American Shoulder and Elbow Surgeons (ASES) score threshold predictive of postoperative ASES and satisfaction scores. We evaluated patients above and below the ROC threshold by comparing their final ASES scores, ASES change (Δ) from baseline, percent maximum outcome improvement (%MOI), and achievement of minimum clinically important differences (MCID), substantial clinical benefit (SCB), and patient-acceptable symptom state (PASS). Fischer exact tests were used to analyze categorical data, while continuous data were analyzed using t-test. RESULTS: A total of 348 patients who underwent rotator cuff repair were included in this study. The preop ASES value predictive of achieving SCB was 63 (area under the curve [AUC], 0.75; 95% confidence interval: 58-67; P < .001). Patients with preoperative ASES less than 63 were significantly more likely to achieve MCID (odds ratio [OR]: 4.7, P < .001) and SCB (OR:6.1, P < .001) and had significantly higher %MOI (63% vs 41%; P = 0.003) and Δ ASES scores (36 vs 12; P < .001). However, patients with preop ASES scores above 63 had significantly higher final ASES scores (86 vs 79; P = .003), were more likely to achieve PASS (59% vs 48%; P = .045), and had higher satisfaction scores (7.4 vs 6.7; P = .024). CONCLUSIONS: Patients with high preop ASES scores achieve less relative improvement; however, these patients may be more likely to achieve PASS and may have higher satisfaction scores postoperatively. LEVEL OF EVIDENCE: Level III, retrospective comparative prognostic trial.

Physician Professional Fees Are Declining and Inpatient and Outpatient Facility Fees Are Increasing for Orthopaedic Procedures in the United States.

PURPOSE: To examine the trends in physician professional fees and inpatient and outpatient facility fees in orthopaedic surgery in the United States. METHODS: Physician professional fees and inpatient and outpatient facility fees were tracked from 2008 to 2021 for the most common orthopaedic procedures in each orthopaedic subspecialty. Using common procedure codes for physician and outpatient procedures and Medicare severity diagnosis related group codes for inpatient procedures, the Medicare Physician Fee Schedules were used to obtain the national payment amounts for physician professional fees and inpatient and outpatient facility fees. Trends in fees were tracked over time after adjustment for inflation. RESULTS: From 2008 to 2021, physician professional fees decreased by an average of 20%, whereas inpatient facility fees increased by 15%, and outpatient facility fees increased by 72%. The orthopaedic subspecialty with the largest decrease in physician professional fees was oncology, with an average decrease of 23.5%, followed by general orthopaedics (23.1%), and sports medicine (22.8%). The largest increase in outpatient facility fees was seen in the subspecialties of general orthopaedics (149.8%), spine (130.1%), and trauma (123.0%). CONCLUSIONS: Over the past 13 years, physician professional fees for the most common orthopaedic procedures have declined while inpatient and outpatient facility fees have increased. Understanding these changes is important to the practice of orthopaedic surgery in the United States. LEVEL OF EVIDENCE: IV, economic.

Sustained release of BMP-2 using self-assembled layer-by-layer film-coated implants enhances bone regeneration over burst release.

Current clinical products delivering the osteogenic growth factor bone morphogenetic protein 2 (BMP-2) for bone regeneration have been plagued by safety concerns due to a high incidence of off-target effects resulting from bolus release and supraphysiological doses. Layer-by-layer (LbL) film deposition offers the opportunity to coat bone defect-relevant substrates with thin films containing proteins and other therapeutics; however, control of release kinetics is often hampered by interlayer diffusion of drugs throughout the film during assembly, which causes burst drug release. In this work, we present the design of different laponite clay diffusional barrier layer architectures in self-assembled LbL films to modulate the release kinetics of BMP-2 from the surface of a biodegradable implant. Release kinetics were tuned by incorporating laponite in different film arrangements and with varying deposition techniques to achieve release of BMP-2 over 2 days, 4 days, 14 days, and 30 days. Delivery of a low dose (0.5 µg) of BMP-2 over 2 days and 30 days using these LbL film architectures was then compared in an in vivo rat critical size calvarial defect model to determine the effect of BMP-2 release kinetics on bone regeneration. After 6 weeks, sustained release of BMP-2 over 30 days induced 3.7 times higher bone volume and 7.4 times higher bone mineral density as compared with 2-day release of BMP-2, which did not induce more bone growth than the uncoated scaffold control. These findings represent a crucial step in the understanding of how BMP-2 release kinetics influence treatment efficacy and underscore the necessity to optimize protein delivery methods in clinical formulations for bone regeneration. This work could be applied to the delivery of other therapeutic proteins for which careful tuning of the release rate is a key optimization parameter.

Reactive oxygen species-degradable polythioketal urethane foam dressings to promote porcine skin wound repair.

Porous, resorbable biomaterials can serve as temporary scaffolds that support cell infiltration, tissue formation, and remodeling of nonhealing skin wounds. Synthetic biomaterials are less expensive to manufacture than biologic dressings and can achieve a broader range of physiochemical properties, but opportunities remain to tailor these materials for ideal host immune and regenerative responses. Polyesters are a well-established class of synthetic biomaterials; however, acidic degradation products released by their hydrolysis can cause poorly controlled autocatalytic degradation. Here, we systemically explored reactive oxygen species (ROS)-degradable polythioketal (PTK) urethane (UR) foams with varied hydrophilicity for skin wound healing. The most hydrophilic PTK-UR variant, with seven ethylene glycol (EG7) repeats flanking each side of a thioketal bond, exhibited the highest ROS reactivity and promoted optimal tissue infiltration, extracellular matrix (ECM) deposition, and reepithelialization in porcine skin wounds. EG7 induced lower foreign body response, greater recruitment of regenerative immune cell populations, and resolution of type 1 inflammation compared to more hydrophobic PTK-UR scaffolds. Porcine wounds treated with EG7 PTK-UR foams had greater ECM production, vascularization, and resolution of proinflammatory immune cells compared to polyester UR foam-based NovoSorb Biodegradable Temporizing Matrix (BTM)-treated wounds and greater early vascular perfusion and similar wound resurfacing relative to clinical gold standard Integra Bilayer Wound Matrix (BWM). In a porcine ischemic flap excisional wound model, EG7 PTK-UR treatment led to higher wound healing scores driven by lower inflammation and higher reepithelialization compared to NovoSorb BTM. PTK-UR foams warrant further investigation as synthetic biomaterials for wound healing applications.

Management of Pathologic Fractures around the Knee: Part 1-Distal Femur.

Pathologic fractures secondary to metastatic disease are an increasingly prevalent problem. Such patients require multidisciplinary collaboration to optimize clinical outcomes. An established algorithm for clinical, laboratory, and radiographic work-up will ensure that each patient achieves the best outcome while avoiding catastrophic complications. Metastatic disease to the region of the knee is less commonly encountered than in other regions of the body, but it presents unique difficulties that merit discussion. Part one of this two-part article series will discuss the appropriate work-up of patients with suspected or impending pathologic fracture of the distal femur, highlight biopsy principles, address perioperative nonsurgical treatments that will optimize patient outcomes, and discuss available surgical treatment modalities.

Management of Metastatic Disease in Long Bones.

LEVEL OF EVIDENCE: Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.

Evaluation and Management of Intra-Articular Tumors of the Knee.

Intra-articular tumors of the knee are most commonly benign. Overall, this is a relatively rare clinical presentation. The differential diagnosis includes pigmented villonodular synovitis, synovial chondromatosis, lipoma arborescens, synovial hemangioma, and very rarely primary sarcoma (synovial sarcoma being the most common). The clinical presentation for these conditions is usually non-specific, but radiographic and advanced imaging findings are able to differentiate some of these tumors. It is essential to obtain and send tissue specimens to pathology for histologic analysis to rule out a primary malignancy as a missed diagnosis can have grave implications on patient outcomes. This review summarized key aspects of diagnosis and treatment for these conditions.

Development of a Risk Stratification Scoring System to Predict General Surgical Complications for Patients Undergoing Foot and Ankle Surgery.

Preventing postoperative complications is crucial for patients, surgeons, and health care facilities. We developed a risk stratification scoring system to optimize postoperative outcomes for patients undergoing foot and ankle surgery. A total of 35,580 patients who underwent foot and ankle procedures from 2005 to 2017 were identified as part of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). To assess the risk of a postoperative complication, we identified several independent risk factors associated with 30-day postoperative complications, then proceeded to develop a point-based risk scoring system. To validate our scoring system, we used it on a cohort of patients from the database who underwent foot and ankle surgery. Risk factors that correlated with postoperative complications included tobacco abuse, age (≥65 years), diabetes mellitus, hypertension, elevated creatinine level (≥1.3 mg/dL), hypoalbuminemia (<3.5 g/dL), chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), hyponatremia (<135 mEq/L), and anemia (hematocrit value, men <42%; women <38%). Point scores for each factor were: anemia, +10; hypoalbuminemia, +9; elevated creatinine level, +6; CHF, +4; diabetes mellitus, +3; hyponatremia, +3; COPD, +2; hypertension, +2; age, +1; and tobacco abuse, +1. For the validation cohort, we stratified patients according to risk as low (0-20 points), medium (21-30 points), and high (≥31 points) risk. In terms of having a postoperative complication, compared with low-risk patients, patients who were at medium risk had an odds ratio of 4.7 (95% CI, 2.8-7.9) and those at high risk had an odds ratio of 8.3 (95% CI, 4.8-14.5). [Orthopedics. 2022;45(3):139-144.].

Management of Primary Aggressive Tumors of the Knee.

Primary bone sarcomas and aggressive benign bone tumors are relatively rare. It is essential to recognize features that are concerning for these aggressive tumors based on a patient's history, physical exam, and radiographs. Physicians and other health care providers should have a high suspicion for these tumors and promptly refer these patients to orthopaedic oncologists. A multidisciplinary, team-based approach is required to obtain an accurate diagnosis and provide comprehensive care. This review discussed the appropriate work-up, biopsy principles, relevant peri-operative medical management, and surgical treatment options for patients with aggressive primary bone tumors around the knee. Primary bone sarcomas (osteosarcoma and chondrosarcoma) and aggressive benign bone tumors (giant cell tumor, chondroblastoma, and chondromyxoid fibroma) that have a predilection to the distal femur and proximal tibia are the focus of this review.

Management of Pathologic Fractures around the Knee: Part 2-Proximal Tibia.

Metastatic disease affecting the proximal tibia is rarer than disease affecting the femur; however, it presents unique challenges that the orthopaedic surgeon must address to ensure successful outcomes and return the patient to an ambulatory status. The essential workup for evaluating and treating these patients is addressed briefly in this review as a summary of the information is provided in part 1 of this series. Part 2 of this series will focus on the surgical treatment of these lesions, which can be complex and is not as well described in the literature. Procedures ranging from open reduction internal fixation with cement augmentation to complex endoprosthetic reconstruction can be employed to address proximal tibia metastatic disease. An awareness of these various treatment modalities allows the orthopaedic surgeon to plan the most effective operation for the patients under their care.

A Competency-based Laparoscopic Cholecystectomy Curriculum Significantly Improves General Surgery Residents' Operative Performance and Decreases Skill Variability: Cohort Study.

OBJECTIVE: To demonstrate the feasibility of implementing a CBE curriculum within a general surgery residency program and to evaluate its effectiveness in improving resident skill. SUMMARY OF BACKGROUND DATA: Operative skill variability affects residents and practicing surgeons and directly impacts patient outcomes. CBE can decrease this variability by ensuring uniform skill acquisition. We implemented a CBE LC curriculum to improve resident performance and decrease skill variability. METHODS: PGY-2 residents completed the curriculum during monthly rotations starting in July 2017. Once simulator proficiency was reached, residents performed elective LCs with a select group of faculty at 3 hospitals. Performance at curriculum completion was assessed using LC simulation metrics and intraoperative operative performance rating system scores and compared to both baseline and historical controls, comprised of rising PGY-3s, using a 2-sample Wilcoxon rank-sum test. PGY-2 group's performance variability was compared with PGY-3s using Levene robust test of equality of variances; P < 0.05 was considered significant. RESULTS: Twenty-one residents each performed 17.52 ± 4.15 consecutive LCs during the monthly rotation. Resident simulated and operative performance increased significantly with dedicated training and reached that of more experienced rising PGY-3s (n = 7) but with significantly decreased variability in performance ( P = 0.04). CONCLUSIONS: Completion of a CBE rotation led to significant improvements in PGY-2 residents' LC performance that reached that of PGY-3s and decreased performance variability. These results support wider implementation of CBE in resident training.

Comparative effectiveness of treatment options for displaced midshaft clavicle fractures : a systematic review and network meta-analysis.

AIMS: The aims of this network meta-analysis (NMA) were to examine nonunion rates and functional outcomes following various operative and nonoperative treatments for displaced mid-shaft clavicle fractures. METHODS: Initial search strategy incorporated MEDLINE, PubMed, Embase, and the Cochrane Library for relevant randomized controlled trials (RCTs). Four treatment arms were created: nonoperative (NO); intramedullary nailing (IMN); reconstruction plating (RP); and compression/pre-contoured plating (CP). A Bayesian NMA was conducted to compare all treatment options for outcomes of nonunion, malunion, and function using the Disabilities of the Arm Shoulder and Hand (DASH) and Constant-Murley Shoulder Outcome scores. RESULTS: In all, 19 RCTs consisting of 1,783 clavicle fractures were included in the NMA. All surgical options demonstrated a significantly lower odds ratio (OR) of nonunion in comparison to nonoperative management: CP versus NO (OR 0.08; 95% confidence interval (CI) 0.04 to 0.17); IMN versus NO (OR 0.07; 95% CI 0.02 to 0.19); RP versus NO (OR 0.07; 95% CI: 0.01 to 0.24). Compression plating was the only treatment to demonstrate significantly lower DASH scores relative to NO at six weeks (mean difference -10.97; 95% CI -20.69 to 1.47). CONCLUSION: Surgical fixation demonstrated a lower risk of nonunion compared to nonoperative management. Compression plating resulted in significantly less disability early after surgery compared to nonoperative management. These results demonstrate possible early improved functional outcomes with compression plating compared to nonoperative treatment. Surgical fixation of mid-shaft clavicle fractures with compression plating may result in quicker return to activity by rendering patients less disabled early after surgery. Cite this article: Bone Jt Open 2021;2(8):646-654.

Oxidation-Responsive, Tunable Growth Factor Delivery from Polyelectrolyte-Coated Implants.

Polyelectrolyte multilayer (PEM) coatings, constructed on the surfaces of tissue engineering scaffolds using layer-by-layer assembly (LbL), promote sustained release of therapeutic molecules and have enabled regeneration of large-scale, pre-clinical bone defects. However, these systems primarily rely on non-specific hydrolysis of PEM components to foster drug release, and their pre-determined drug delivery schedules potentially limit future translation into innately heterogeneous patient populations. To trigger therapeutic delivery directly in response to local environmental stimuli, an LbL-compatible polycation solely degraded by cell-generated reactive oxygen species (ROS) was synthesized. These thioketal-based polymers were selectively cleaved by physiologic doses of ROS, stably incorporated into PEM films alongside growth factors, and facilitated tunable release of therapeutic bone morphogenetic protein-2 (BMP-2) upon oxidation. These coatings' sensitivity to oxidation was also dependent on the polyanions used in film construction, providing a simple method for enhancing ROS-mediated protein delivery in vitro. Correspondingly, when implanted in critically-sized rat calvarial defects, the most sensitive ROS-responsive coatings generated a 50% increase in bone regeneration compared with less sensitive formulations and demonstrated a nearly threefold extension in BMP-2 delivery half-life over conventional hydrolytically-sensitive coatings. These combined results highlight the potential of environmentally-responsive PEM coatings as tunable drug delivery systems for regenerative medicine.

Can an outpatient risk assessment tool predict who needs postoperative haemoglobin monitoring?

AIMS: Recent improvements in surgical technique and perioperative blood management after total joint replacement (TJR) have decreased rates of transfusion. However, as many surgeons transition to outpatient TJR, obtaining routine postoperative blood tests becomes more challenging. Therefore, we sought to determine if a preoperative outpatient assessment tool that stratifies patients based on numerous medical comorbidities could predict who required postoperative haemoglobin (Hb) measurement. METHODS: We performed a prospective study of consecutive unilateral primary total knee arthroplasties (TKAs) and total hip arthroplasties (THAs) performed at a single institution. Prospectively collected data included preoperative and postoperative Hb levels, need for blood transfusion, length of hospital stay, and Outpatient Arthroplasty Risk Assessment (OARA) score. RESULTS: A total of 504 patients met inclusion criteria. Mean age at time of arthroplasty was 65.3 years (SD 10.2). Of the patients, 216 (42.9%) were THAs and 288 (57.1%) were TKAs. Six patients required a blood transfusion postoperatively (1.19%). Transfusion after surgery was associated with lower postoperative day 1 Hb (median of 8.5 (interquartile range (IQR) 7.9 to 8.6) vs 11.3 (IQR 10.4 to 12.2); p < 0.001), longer length of stay (1 day (IQR 1 to 1) vs 2 days (IQR 2 to 3); p < 0.001), higher OARA score (median of 60.0 (IQR 40 to 75) vs 5.0 (IQR 0-35); p = 0.001), and total hip arthroplasty (p < 0.001). All patients who received a transfusion had an OARA score > 34; however, this did not reach statistical significance as a screening threshold. CONCLUSION: Risk of blood transfusion after primary TJR was uncommon in our series, with an incidence of 1.19%. Transfusion was associated with OARA scores > 60. The OARA score, not American Society of Anesthesiologists grade, reliably identified patients at risk for postoperative blood transfusion. Selective Hb monitoring may result in substantial cost savings in the era of cost containment. Cite this article: Bone Joint J 2021;103-B(1):65-70.