Occupational hazards and pregnancy in orthopaedics: female surgeons are at increased risk of infertility and pregnancy complications.

Female surgeons have increased rates of infertility and pregnancy complications compared to the general population. Reported infertility rates in surgeons are 32% compared to 10.9% in the general population. Reported pregnancy complication rates in surgeons range from 25% to 35%. In the orthopaedic operating theatre occupational hazards that have an effect on pregnancy outcomes include radiation, exposure to methyl methacrylate in bone cement, surgical smoke, sharps injuries, exposure to anaesthetic waste gases and the effects of the physical demands of surgery including prolonged work hours and night shift work. Outside the operating theatre exposure to nitrous oxide, formaldehyde, surgical scrub also have evidence of negative pregnancy outcomes. This review summarizes the available evidence as it relates to specific occupational hazards that face health workers in an orthopaedic operating theatre. This information, while targeted at orthopaedic health workers, is also relevant to anaesthetists, radiographers, nursing staff, medical device company representatives and female surgeons in other specialties.

Medium-term results of inlay vs. onlay humeral components for reverse shoulder arthroplasty: a New Zealand Joint Registry study.

BACKGROUND: The purpose of this study was to compare medium-term results of inlay and onlay humeral components in reverse shoulder arthroplasty (RSA). Specifically, we report differences in revision rate and functional outcomes between the 2 designs. METHODS: The 3 most used inlay (in-RSA) and onlay (on-RSA) implants by volume from the New Zealand Joint Registry were included in the study. In-RSA was defined as having a humeral tray that recessed within the metaphyseal bone, whereas on-RSA was defined as having a humeral tray that rested on the epiphyseal osteotomy surface. The primary outcome was revision up to 8 years postsurgery. Secondary outcomes included the Oxford Shoulder Score (OSS), implant survival, and revision cause for in-RSA and on-RSA as well as individual prostheses. RESULTS: There were 6707 patients (5736 in-RSA; 971 on-RSA) included in the study. For all causes, in-RSA demonstrated a lower revision rate compared to on-RSA (revision rate/100 component years: in-RSA 0.665, 95% confidence interval [CI] 0.569-0.768; on-RSA 1.010, 95% CI 0.673-1.415). However, the mean 6-month OSS was higher for the on-RSA group (mean difference 2.20, 95% CI 1.37-3.03; P < .001). However, this was not clinically significant. At 5 years, there were no statistically or clinically significant differences between the 2 groups with respect to the OSS. CONCLUSION: The medium-term survival of in-RSA was higher than that of on-RSA. However, functional outcomes at 6 months were better for on-RSA compared to in-RSA. Further follow-up is required to understand the long-term survivorship and functional outcomes between these designs.

The lifetime revision risk of primary anatomic and reverse total shoulder arthroplasty.

BACKGROUND: Implant survival in total shoulder arthroplasty (TSA) is currently defined with reference to a set time period (eg, 5-year implant survival). This is a difficult concept for patients to understand, especially for younger patients who have more years of life remaining. Our study aims to calculate a patient's lifetime revision risk after primary anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty-a more meaningful projection of revision risk over a patient's remaining lifetime. METHODS: The New Zealand Joint Registry (NZJR) and national death data was used to calculate the incidence of revision and mortality in all patients who underwent primary aTSA and rTSA in New Zealand between 1999 and 2021. Lifetime revision risk was calculated using previously described methods, and this risk was stratified by age (46-90 years, 5-year bins), sex, and procedure type (aTSA and rTSA). RESULTS: In total, there were 4346 patients in the aTSA cohort and 7384 patients in the rTSA cohort. Lifetime revision risk was highest in the youngest age group (46-50 years) at 35.8% (95% CI 34.5%-37.0%) for aTSA and 30.9% (95% CI 29.9%-32.0%) for rTSA, with risk decreasing with increasing age. Across all age groups, the lifetime revision risk was higher for aTSA compared to rTSA. By sex, females reported higher lifetime revision risk for each age group in the aTSA cohort whereas males reported higher lifetime revision risk for each group in the rTSA cohort. CONCLUSIONS: Our study demonstrates that younger patients have higher lifetime revision risk after total shoulder arthroplasty. Our results highlight the long-term revision risks associated with the trend of offering shoulder arthroplasty to younger patients. The data may be used among various health care stakeholders to inform the surgical decision-making process and plan for future health care resource use.

Re-tears after rotator cuff repair: Current concepts review.

Re-tear following rotator cuff repair is common and has been reported to range from between 13 and 94% despite satisfactory clinical outcomes following rotator cuff surgery. Various risk factors have been associated with an increased tear rate, including patient factors, tear and shoulder morphology, repair technique, and rehabilitation regimes. Different modes of rotator cuff failure have been described. The management of re-tear in patients following rotator cuff repair is challenging and depends on the age, functional status and requirements of the patient, and re-tear size and residual tendon length. This article aims to review the factors associated with rotator cuff re-tear. It describes which of these are associated with poor clinical outcomes, and discusses the long-term outcomes of re-tear and treatment options.

Measurement of Scaphoid Bone Microarchitecture: A Computed Tomography Imaging Study and Implications for Screw Placement.

PURPOSE: High bone density and quality is associated with improved screw fixation in fracture fixation. The objective of this study was to assess bone density and quality in the proximal and distal scaphoid to determine optimum sites for placement of 2 screws in scaphoid fracture fixation. METHODS: Twenty-nine cadaveric human scaphoid specimens were harvested and scanned using micro-computed tomography. Bone density (bone volume fraction) and bone quality (relative bone surface area, trabecular number, and trabecular thickness) were evaluated in 4 quadrants within each of the proximal and distal scaphoid. RESULTS: The proximal radial quadrant of the scaphoid had significantly greater bone volume than the distal ulnar (mean difference, 33.2%) and distal volar quadrants (mean difference, 32.3%). There was a significantly greater trabecular number in the proximal radial quadrant than in the distal ulnar (mean difference, 16.7%) and in the distal volar quadrants (mean difference, 15.9%) and between the proximal ulnar and the distal ulnar quadrants (mean difference, 12%). There was a significantly greater bone surface area in the proximal radial and distal radial quadrants than in the distal ulnar and distal volar quadrants. There were no significant differences in trabecular thickness between the 8 analyzed quadrants CONCLUSIONS: Although there are differences in bone volume, trabecular number, and bone surface area between the proximal pole of the scaphoid and that of the distal pole, there were no significant differences in the bone quality (trabecular thickness, trabecular number, and relative bone surface area) and density (bone volume fraction) between the 4 quadrants of the proximal or distal pole of the cadaveric scaphoids studied. CLINICAL RELEVANCE: Insertion of 2 headless compression screws can be determined by ease of surgical access and ease of screw positioning and not by differences in bone quality or density of the proximal or distal scaphoid.

Evaluation of the performance of three tenodesis techniques for the treatment of scapholunate instability: flexion-extension and radial-ulnar deviation.

Chronic scapholunate ligament (SL) injuries are difficult to treat and can lead to wrist dysfunction. Whilst several tendon reconstruction techniques have been employed in the management of SL instability, SL gap reappearance after surgery has been reported. Using a finite element model and cadaveric study data, we investigated the performance of the Corella, scapholunate axis (SLAM) and modified Brunelli tenodesis (MBT) techniques. Scapholunate dorsal and volar gap and angle were obtained following virtual surgery undertaken using each of the three reconstruction methods with the wrist positioned in flexion, extension, ulnar deviation and radial deviation, in addition to the ulnar-deviated clenched fist and neutral positions. From the study, it was found that, following simulated scapholunate interosseous ligament rupture, the Corella technique was better able to restore the SL gap and angle close to the intact ligament for all wrist positions investigated, followed by SLAM and MBT. The results suggest that for the tendon reconstruction techniques, the use of multiple junction points between scaphoid and lunate may be of benefit. Graphical abstract The use of multiple junction points between scaphoid and lunate may be of benefit for tendon reconstruction techniques.

Scaphoid Fracture Fixation in a Nonunion Model: A Biomechanical Study Comparing 3 Types of Fixation.

PURPOSE: Union of a scaphoid fracture after fixation is influenced by various factors, one of which is fracture stability. This study aims to compare the biomechanical stability of 3 different types of scaphoid fracture fixation in a scaphoid nonunion model. METHODS: Thirty cadaveric scaphoid specimens were assigned to one of 3 different fixation groups: (1) single 3.0-mm compression screw, (2) two 2.2-mm screws, and (3) scaphoid plate. A 3-mm volar wedge osteotomy was created at the scaphoid waist to simulate a nonunion model. The primary outcome measure was load to failure, whereas secondary outcome measures were load to 2-mm displacement, energy absorbed, stiffness, and mode of failure, recorded by video and retrieval analysis. RESULTS: There was a significantly lower load to failure in the single screw construct compared with that in the double screw (mean difference 187.2 N) and plate fixation constructs (mean difference 150.7 N). The mean load to 2-mm displacement in the single screw construct (91.5 N) was also significantly lower than that in the double screw (181.8 N) and plate fixation constructs (197.2 N). There was a significantly lower stiffness with the single screw fixation compared with that of the double screws (mean difference 85.4 N/mm), and lower energy absorbed with single screws when compared with that of double screws (mean difference 386.5 mJ) and when compared with plate fixation (mean difference 270.8 mJ). CONCLUSIONS: In this biomechanical study comparing fixation methods using a model of scaphoid nonunion with bone loss, we found that double screws or plate fixation demonstrated significantly greater stability, stiffness, and energy absorption when compared with a single compression screw. We found no discernible differences between double screw fixation and the plate groups. CLINICAL RELEVANCE: The use of double screws or plate fixation in a nonunion setting may allow accelerated rehabilitation without compromise to fracture stability.

Radial Column Excision and Four-Corner Fusion for the Treatment of Basal Thumb Arthritis and Scapholunate Advanced Collapse Wrist or Midcarpal Arthritis.

Background The combination of trapeziometacarpal arthritis and intercarpal pattern of degenerative wrist arthritis is uncommon. Purpose To report on the clinical and radiologic results of patients who have undergone radial column excision (scaphoidectomy and trapeziectomy) (RCE) and four-corner fusion (4CF). We describe the patterns of disease that present with basal thumb and midcarpal arthritis and treatment outcomes of a single-surgeon series. Patients and Methods A consecutive series of seven patients underwent RCE and 4CF over a 2-year period, for basal thumb osteoarthritis with concurrent degenerative midcarpal wrist arthritis. Six patients were available for review. All six patients were women with a mean age of 73 years (range: 67-78; SD 4.6). Mean follow-up time was 48.2 months (34-59 months). Radiographic and clinical outcomes were recorded for all patients, to include wrist range of motion, key pinch, grip strength, and patient-rated wrist evaluation (PRWE). Results There were no failures or revision procedures. The mean range of motion was flexion of 40 degrees (range: 30-40 degrees), extension of 30 degrees (range: 20-42 degrees), radial deviation of 18 degrees (range: 10-30 degrees), and ulnar deviation of 15 degrees (range: 0-25 degrees). The mean key pinch was 4.2 kg (range: 0.5-10, SD ± 3.5) and mean grip strength was 9.4 kg (range: 0-19, SD ± 8.9). The PRWE results in four patients were within normal values. Conclusion RCE with 4CF resulted in acceptable clinical outcomes in four of six patients treated, with no failures at a mean follow-up of 48.2 months. Level of Evidence Level IV, therapeutic study.

Analysis of tenodesis techniques for treatment of scapholunate instability using the finite element method.

Chronic scapholunate ligament (SL) injury is a common disorder affecting the wrist. Despite advances in surgical techniques used to treat this injury, SL gap re-emergence may occur postoperatively. This paper presents an investigation into the performance of the Corella, schapolunate axis (SLAM), and modified Brunelli tenodesis (MBT) surgical reconstruction techniques used to treat scapholunate instability. Finite element (FE) models were used to undertake virtual surgery, and the resulting scapholunate (SL) gap and angle obtained using the 3 techniques were compared. The Corella technique was found to achieve the SL gap and angle closest to the intact (ligament) wrist, restoring SL gap and angle to within 5.6% and 0.6%, respectively. The MBT method resulted in an SL gap least close to the intact. The results of our study indicate that the contribution of volar scapholunate interosseous ligament to scapholunate stability could be important.

Classifying cerebral palsy: are we nearly there?

BACKGROUND: Cerebral palsy (CP) is the most common cause of physical disability in childhood in developed countries and encompasses a wide range of clinical phenotypes. Classification of CP according to movement disorder or topographical distribution is widely used. However, these classifications are not reliable nor do they accurately predict musculoskeletal pathology. More recently, the Gross Motor Function Classification System (GMFCS) has been introduced and its validity, reliability, and clinical utility have been confirmed. In 2005 it was suggested that children should be described and classified according to the GMFCS in all outcome studies involving children with CP, in the Journal of Pediatric Orthopaedics (JPO). This study aimed to describe utilization of the GMFCS in 3 journals: Journal of Bone and Joint Surgery (JBJS Am), JPO, and Developmental Medicine and Child Neurology (DMCN), over a 7-year period (2005 to 2011), and any relationship to the journal's impact factor. A secondary aim was to establish if differences in methodological quality existed between those studies utilizing GMFCS and those that did not. METHODS: A targeted literature search of the 3 selected journals using the term "cerebral palsy" was conducted using the Medline database. Utilization of the GMFCS was assessed using report of these data in the methods or results section of the retrieved papers. The Methodological Index for Non-Randomized Studies (MINORS) was employed to evaluate the quality of papers published in JPO. RESULTS: One hundred and fifty-four studies met the inclusion criteria and in 85 (68%) the GMFCS was used. Of these, 112 were published in JPO, of which 51 (46%) utilized the GMFCS, compared with 72% for JBJS Am, and 88% for DMCN. In the JPO, utilization of the GMFCS improved from 13% to 80%, over the 7-year study period. CONCLUSIONS: Utilization of the GMFCS has increased rapidly over the past 7 years in the JPO but there is room for further improvement. LEVEL OF EVIDENCE: Not applicable.

Significance of sentinel infective events in haematogenous prosthetic knee infections.

BACKGROUND: Infection after primary knee arthroplasty is devastating. The aim of this study was to determine the significance of sentinel infective events prior to the development of haematogenous prosthetic knee infection. METHODS: A retrospective single-centre case control study of 1641 primary knee arthroplasties was conducted between 1998 and 2006. Seventeen haematogenous prosthesis infections were identified and were matched with 51 controls. Perioperative data were collected prospectively, and co-morbidities, infection parameters and sentinel events were collected from patient files and questionnaires. Analysis was performed between controls and the 17 haematogenous infections. RESULTS: The overall prosthetic infection rate was 2.2%. Acute infections accounted for 1.2% with late haematogenous accounting for 1%. The mean time to infection in the haematogenous infection group was 2.3 years (range 3 months to 11 years), and the mean follow-up was 3.8 years (range 7 months to 11 years). Significant risk factors included the number of co-morbidities (relative risk 3.4) and a sentinel event of cellulitis (relative risk 2.7). Fifteen of 17 cases described a sentinel event prior to infection compared with 31 of 51 controls (P= 0.041). The commonest preceding event was skin or soft tissue infection in nine (53%) cases. The most common infecting organism was Staphylococcus aureus in 12 patients (four methicillin-resistant Staphylococcus aureus, eight methicillin-sensitive Staphylococcus aureus). CONCLUSIONS: Fifteen of 17 (88%) patients who developed late haematogenous infection had a preceding sentinel event with the commonest source being skin and soft tissue infection. Haematogenous infections are more likely to occur in patients with multiple co-morbidities.