Pre-operative planning for reverse shoulder arthroplasty in low-resource centres: A modified Delphi study in South Africa.

BACKGROUND: Pre-operative planning for reverse shoulder arthroplasty (RSA) poses challenges, particularly when dealing with glenoid bone loss. This modified Delphi study aimed to assess expert consensus on RSA planning processes and rationale, specifically targeting low-resourced institutions. Our objective was to offer pre-operative decision-making algorithms tailored for surgeons practising in resource-constrained hospitals with limited access to computed tomography (CT) scans. METHODS: A working group generated statements on pre-operative imaging and glenoid of glenoid morphology and intra-operative decision-making. The study was conducted in three stages, with virtual consensus meetings in between. Stages 2 and 3 consisted only of closed questions/statements. The statements with over 70% were considered consensus achieved and those with less than 10% were considered disagreement consensus achieved. RESULTS: Twelve shoulder surgeons participated, with 67% having over five years of experience in shoulder arthroplasty. In the absence of glenoid bone loss, the sole use of plain radiographs for pre-operative planning reached consensus and is recommended by these groups, while 100% advise using CT scans when bone loss is present. Most surgeons (70%) recommend using patient-specific instrumentation (PSI) in cases of structural bone loss. Most of the statements on intra-operative decision-making related to component placement and enhancing stability failed to reach consensus. CONCLUSION: While consensus was achieved on most aspects of pre-operative imaging and planning, technical aspects of surgery lacked consensus. Planning for patients with structural glenoid bone loss necessitates CT scans and planning tools.

Developing an antibiogram for empiric antibiotic prescribing for adult non-spinal orthopaedic infections in a developing world setting.

PURPOSE: Empiric antibiotic strategies in the treatment of fracture-related infections, chronic osteomyelitis, prosthetic joint infection, and septic arthritis should be based on local microbiological antibiograms. This study aims to describe the microbiology and review the antibiogram profiles of bacterial isolates from patients undergoing surgical treatment for non-spinal orthopaedic infections, to identify the most appropriate empiric antibiotic strategy. METHODS: A retrospective review was performed of all cases of non-spinal orthopaedic infections treated surgically from 1 January 2018 to 31 December 2018. The National Health Laboratory Service microbiology database was used to identify all intra-operative microbiological specimens obtained from orthopaedic patients, and data were correlated with the orthopaedic surgical database. Cases were divided into fracture-related infections, chronic osteomyelitis, prosthetic joint infection, and septic arthritis. Antibiotic susceptibility data were used to predict the efficacy of different empiric antibiotic regimens. RESULTS: A total of 107 cases were included in the study; 184 organisms were cultured. Overall, the most common organism cultured was Staphylococcus aureus (25%) followed by Acinetobacter baumannii (9%), Enterococcus faecalis (7%) and Enterobacter cloacae (5%). Across all categories the oral antibiotic combination with the highest effectiveness (81%) would have been a combination of co-trimoxazole, ciprofloxacin and amoxicillin. The most effective intravenous antibiotic combination would have been either piperacillin-tazobactam, amikacin and vancomycin or meropenem and vancomycin; 90% of tested isolates were susceptible to either of these combinations. CONCLUSION: Antibiogram profiles can serve to guide to empiric antibiotic choice in the management of different categories of non-spinal orthopaedic infections.

Moment arms of the coracobrachialis and short head of biceps following a Latarjet procedure: a modeling study.

BACKGROUND: The Latarjet procedure transfers the coracoid process to the anterior glenoid. This prevents recurrent anterior humeral dislocation but alters the origins of the coracobrachialis (CBR) and short head of the biceps (SHB). The impact of this alteration on the moment arms of these muscles has not been examined. METHODS: The Newcastle Shoulder Model was updated with 15 healthy cadaveric bone models to create customized shoulder models. The CBR and SHB muscles were attached to the anterior glenoid via an elliptical wrapping object. Muscle moment arms were calculated for abduction, forward flexion, scapular plane elevation, and internal rotation with 20° and 90° of abduction. Statistical comparison of moment arms between native and Latarjet shoulders was performed using spm1D. RESULTS: By transferring the origins of the CBR and SHB to the anterior glenoid, both muscles had extension moment arms during glenohumeral elevation in the coronal, sagittal, and scapular planes. Their average moment arms during abduction (-30.4 ± 3.2 mm for CBR and -29.8 ± 3.0 mm for SHB) and forward flexion (-26.0 ± 3.1 mm for CBR and -26.2 ± 3.2 mm for SHB) suggested that their role after the Latarjet procedure changed compared with their role in the native shoulder (P < .001). At higher abduction levels, both the muscles had higher internal rotation moment arms compared with the native shoulder. CONCLUSION: The Latarjet procedure affected the moment arms of the CBR and SHB. Both muscles had increased extension and internal rotation moment arms at higher degrees of elevation compared with the native shoulders. This finding suggests that these muscles act as dynamic stabilizers after the Latarjet procedure.

A narrative review of treatment strategies for major glenoid defects during primary reverse shoulder arthroplasty, with a focus on the use of structural bone graft.

Structural glenoid defects are common during primary reverse shoulder arthroplasty (RSA) and are often associated with poor outcomes. The lack of pre-operative imaging protocols for determining the depth and degree of glenoid wear hinders our ability to accurately plan and correct these defects. Although bone grafting has been reported to be effective in reducing glenoid wear during RSA, there is limited information on when to utilise it and how to prepare the graft. We conducted this review to assess the evidence for the management of glenoid defects, with an emphasis on bone grafts to treat structural glenoid bone loss in primary RSA patients.

Surgical management of distal humerus gunshot fractures: descriptive case series.

PURPOSE: The purpose of this study was to report our 5 years surgical experience and the rate of neurovascular injury following gunshot fractures of the distal humerus in a in level-1 Trauma Centre in South Africa. METHODS: A retrospective case series of 25 consecutive adult gunshot injuries to the distal humerus. Demographic and injury data were extracted from clinical case notes and electronic operative records. Imaging archives were used to classify fractures according to the AO/OTA classification. RESULTS: Twenty-five male patients, with mean age of 32-years-old, sustained gunshot injuries to the distal humerus. Eleven patients had multiple gunshots. Forty-four percent of patients underwent Computed Tomography Angiography (CTA), 20% had confirmed brachial artery injury. Limbs with vascular injury were salvaged with arterial repair and external fixation. Fractures were extra-articular in 20 cases (80%). Nineteen fractures were classified as highly comminuted. Nerve injuries occurred in 52% and were all managed expectantly. Only 32% of patients attended follow-up beyond 3 months. CONCLUSIONS: These are rare challenging injuries with high rates of neurovascular damage. This demographic of patients is poorly compliant with follow up highlighting the need for high-quality early care. Brachial artery injury should be excluded with CTA and can be managed with arterial repair and external fixation. All fractures in this series were surgically managed with conventional anatomical plate and screw fixation techniques. For nerve injury, we advocate expectant management. LEVEL OF EVIDENCE: IV.

Characterizing moment arms of the coracobrachialis and short head of biceps in native shoulders and after reverse total shoulder arthroplasty during elevation and rotation: a modeling study.

BACKGROUND: Reverse total shoulder arthroplasty (RTSA) alters the line of action of muscles around the glenohumeral joint. The effects of these changes have been well characterized for the deltoid, but there is limited information regarding the biomechanical changes to the coracobrachialis (CBR) and short head of biceps (SHB). In this biomechanical study, we investigated the changes to the moment arms of the CBR and SHB due to RTSA using a computational model of the shoulder. METHODS: The Newcastle Shoulder Model, a pre-validated upper-extremity musculoskeletal model, was used for this study. The Newcastle Shoulder Model was modified with bone geometries obtained from 3-dimensional reconstructions of 15 nondiseased shoulders, constituting the native shoulder group. The Delta XTEND prosthesis, with a glenosphere diameter of 38 mm and polyethylene thickness of 6 mm, was virtually implanted in all the models, creating the RTSA group. Moment arms were measured using the tendon excursion method, and muscle length was calculated as the distance between the muscle's origin and insertion points. These values were measured during 0°-150° of abduction, forward flexion, scapular-plane elevation, and -90° to 60° of external rotation-internal rotation with the arm at 20° and 90° of abduction. Statistical comparisons between the native and RTSA groups were analyzed using 1-dimensional statistical parametric mapping (spm1D). RESULTS: Forward flexion moment arms showed the greatest increase between the RTSA group (CBR, 25.3 ± 4.7 mm; SHB, 24.7 ± 4.5 mm) and native group (CBR, 9.6 ± 5.2 mm; SHB, 10.2 ± 5.2 mm). The CBR and SHB were longer in the RTSA group by maximum values of 15% and 7%, respectively. Both muscles had larger abduction moment arms in the RTSA group (CBR, 20.9 ± 4.3 mm; SHB, 21.9 ± 4.3 mm) compared with the native group (CBR, 19.6 ± 6.6 mm; SHB, 20.0 ± 5.7 mm). Abduction moment arms occurred at lower abduction angles in the RTSA group (CBR, 50°; SHB, 45°) than in the native group (CBR, 90°; SHB, 85°). In the RTSA group, both muscles had elevation moment arms until 25° of scapular-plane elevation motion, whereas in the native group, the muscles only had depression moment arms. Both muscles had small rotational moment arms that were significantly different between RTSA and native shoulders during different ranges of motion. CONCLUSION: Significant increases in elevation moment arms for the CBR and SHB were observed in RTSA shoulders; these increases were most pronounced during abduction and forward elevation motions. RTSA also increased the lengths of these muscles.

Evaluating Basic Knee Arthroscopy Skills in Orthopaedic Trainees in a Limited-Resource Setting.

Orthopaedic training in Southern Africa is largely focused on trauma, although elective procedures, such as knee arthroscopy, are increasing. This is especially true in the private sector where most trainees will practice. The primary aim of this study was to assess the arthroscopic competency of orthopaedic trainees in a setting of limited resources. Methods: A prospective observational cohort study was conducted. Orthopaedic trainees of a Southern African university hospital performed basic arthroscopy on a knee model. Their surgical competency was assessed by 2 surgeons proficient in arthroscopy using the modified Basic Knee Arthroscopy Skill Scoring System (mBAKSSS). Results: A total of 16 trainees (12 male) were included (6 junior and 10 senior trainees). The median age of participants was 36 (34.8-37) years. The median mBAKSSS was 28.0 (20.3-32.5) but showed a large variability (12.0-42.5). The overall reliability was excellent with Cronbach's alpha of 0.91 and interclass correlation of 0.91 (95% confidence interval 0.75-0.97). Conclusions: The average knee arthroscopy proficiency of our trainees is comparable with that of international training programs, but there was great variability with inconsistent skills among the trainees. This calls for improved and reproducible arthroscopy training and skills transfer, exposure to procedures, and ongoing assessment. Level of Evidence: II (prospective observational cohort study).

Return to rugby following musculoskeletal injuries: A survey of views, practices and barriers among health and sport practitioners.

STUDY DESIGN AND SETTING: Returning rugby players to the sport following musculoskeletal injuries is a multi-factorial and challenging process. A cross-sectional observational study was conducted among health and sport practitioners involved with injured rugby players in South Africa. OBJECTIVES AND OUTCOME MEASURES: The views, current practices and barriers encountered by health and sport practitioners during return to rugby were investigated using a self-developed online survey. RESULTS: 64 practitioners participated in the survey including physiotherapists, orthopaedic surgeons, biokineticists and sports physicians. Return to sport (RTS) protocols were considered important, however, participants also indicated that they were slightly more likely to use anecdotal protocols compared to published protocols. Time frames, stages of healing, pain and subjective ratings along with functional outcome measures (such as range of motion, muscle function and proprioception) and sport-specific skills were rated as important and commonly utilised in different RTS phases (i.e., return to non-contact, return to contact and return to matches). The most commonly perceived barriers encountered were related to lack of access and time-constraints. CONCLUSION: Return to rugby guidelines with consideration of a broad range of criteria and common barriers encountered should be developed to facilitate safe, practical and time-efficient return to rugby following musculoskeletal injuries.

Return to play protocols for musculoskeletal upper and lower limb injuries in tackle-collision team sports: A systematic review.

Athletes in tackle-collision teams are at high risk of musculoskeletal injuries resulting in absence from play due to the high impact nature of the sport. There is a paucity of research to guide the management and assessment methods needed to facilitate the return to play (RTP) process. This review aimed to describe, synthesise and evaluate RTP protocols implemented for musculoskeletal injuries in tackle-collision teams. A systematic search of Scopus, PubMed, Web of Science and Ebsco Host was conducted for RTP management protocols and assessment modalities following upper and lower limb musculoskeletal injuries in tackle-collision team athletes. Prospective and retrospective quantitative controlled trials, cohort, case-control, case-series and cross-sectional observation studies published between January 2000 and March 2020 were considered. The main outcome measures were the proportion of athletes to RTP, associated time-loss and reinjury risk. 5265 articles were screened. 34 studies met the eligibility criteria of which 23 involved management and 11 assessment modalities. Management involved surgical or conservative strategies along with exercise-based rehabilitation. Assessment modalities included radiographic assessment, clinical evaluation and subjective ratings. Promising RTP management included progressive weight-bearing and exercised-based rehabilitation for ankle sprains as well as surgery, the use of a sling and exercise-based rehabilitation for shoulder instability. MRI scans showed promise in predicting time-loss following hamstring and calf strains in tackle-collision athletes. There are currently no clear guidelines for RTP after musculoskeletal injuries in tackle-collision sports. Future research should investigate efficient management strategies evaluated through valid and reliable assessment methods to better guide clinicians.

Development of a framework to assess the biomechanical impact of reverse shoulder arthroplasty placement modifications.

Reverse shoulder arthroplasty biomechanics can be improved by modifying the placement of prosthesis. Biomechanical studies have quantified the impact of placement modifications on the mobility and stability of the reverse shoulder. While these studies have provided detailed insights, direct comparisons between their finding are obfuscated by their use of differing methodologies. The aim of our study was to develop an assessment framework which used musculoskeletal simulations to consistently evaluate the biomechanics of various placement modifications. We conducted musculoskeletal simulations of humeral elevations and rotations using 15 reverse shoulder models. For each model, these simulations were conducted for a reference configuration of the prosthesis, established using surgical guidelines, and 34 modified configurations, which were based on commonplace adaptations to the placement of the glenosphere and humeral tray. The effect of each modified configuration on deltoid elongation, deltoid moment arm (DMA), joint stability, and impingement-free range of motion (IFROM) was determined relative to the reference configuration. We found that 16 of the 34 modified placements had an overall beneficial impact on reverse shoulder biomechanics. Within this subset, we identified two biomechanical trade-offs. First, there is an antagonistic relationship between IFROM and both the DMA and joint stability. Second, functional requirements differ between humeral elevations and rotations. Furthermore, we found that posteromedial translation of the humeral tray had the most beneficial impact on joint stability and inferior translation of the glenosphere had the most beneficial impact on IFROM and DMA.

Identification of recurring scapular fracture patterns using 3-dimensional computerized fracture mapping.

BACKGROUND: Scapular fracture fixation and implant selection are guided by the fracture pattern and classification, which requires accurate understanding and interpretation of the fracture lines. Three-dimensional (3D) computed tomography (CT)-based fracture pattern analysis enhances a more accurate understanding of the scapular fracture patterns. The purpose of this study was to create scapular fracture maps and identify the frequent fracture patterns using 3D reconstructed CT images. METHOD: Seventy patients treated for scapular fractures, in a single hospital, were considered for this study. Their CT images were reconstructed into 3D models and the fracture fragments were virtually reduced. The reduced 3D models were first aligned on a 3D template and 2D images were captured on the anterior, posterior, and lateral views. Then each fracture image was aligned on a corresponding 2D template and the fracture lines were transferred to the template. The 3 separate views were used to accurately capture the propagation and exit of the fractures through the scapular anatomy. These fracture lines were compiled and heat maps were generated to identify the frequent fracture zones of the scapula. RESULT: The observed scapular fractures propagated through multiple regions of the bone. Overall, the 3 most common exit zones in the scapula were the lateral (69%), medial (67%), and superior borders (60%). More specifically, the superior lateral border, medial base of the scapula spine, spinoglenoid notch, and mid-superior border were the most frequent zones of fracture in the scapular body. Simple intra-articular fractures (transverse or oblique type) were the most common (92%) fracture type in the glenoid region. CONCLUSION: Scapular fractures reveal repeatable patterns. The zones of recurrent fracture patterns can be identified from fracture and heat maps. Graphical plots of fracture and heat maps may assist surgical planning and implant design optimization.

Simultaneous or Staged Bilateral Arthroscopic Rotator Cuff Repair: An Observational Study of Intraoperative and Postoperative Outcomes.

BACKGROUND: Bilateral arthroscopic rotator cuff repair (ARCR) is frequently performed in patients with symptomatic bilateral rotator cuff tears. PURPOSE: To compare patient-reported outcomes and mobility between simultaneous and staged bilateral ARCR. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Included were 51 patients who underwent simultaneous (anesthetized once) and 42 patients who underwent staged (anesthetized twice) bilateral ARCR between January 2014 and January 2018; for the staged group, the interval between procedures was at least 12 months. All operations were performed by the same surgeon, and all patients had minimum 24-month follow up in both shoulders. Patient-reported outcomes and range of motion (ROM) were assessed preoperatively and postoperatively and compared between groups. Outcome measures included the Constant-Murley score (CMS) and American Shoulder and Elbow Surgeons (ASES) score as well as measures of psychological status, health-related quality of life, activities of daily living (ADL), and patient satisfaction with the state of one's shoulders. RESULTS: The mean follow-up times for the staged and simultaneous ARCR groups were 44.1 months (range, 36-60 months) and 37.5 months (range, 25-59 months), respectively. There were no significant differences in age, tear size, or fatty degeneration of rotator cuff muscles between the groups. The cumulative length of hospital stay in the staged group was significantly longer than in the simultaneous group (P < .001). At the final follow-up, both groups showed significant improvement in ROM, CMS, and ASES scores (P < .05). No significant differences between the groups were observed in terms of ROM, CMS, and ASES scores postoperatively. At 24 months postoperatively, psychological status and health-related quality of life in both groups improved significantly (P < .05), and there were no significant between-group differences. Patients were able to perform most essential ADL. Both groups had high patient satisfaction, but patient satisfaction for the second shoulder of the staged group was lower than that of the simultaneous group (P = .039). CONCLUSION: Simultaneous bilateral ARCR was shown to be effective, resulting in similar improvements in clinical outcomes to staged bilateral ARCR at 2-year follow-up. In addition to higher patient satisfaction, simultaneous bilateral ARCR also had a shorter treatment cycle.

Development and Validation of a Simplified Chinese Version and a Face-Scale Version of the Oxford Shoulder Score: A 2-Center Prospective Study.

BACKGROUND: There has not yet been a pictorial version of a patient-reported outcome measure for shoulder pain. PURPOSE: To translate the English version of the Oxford Shoulder Score (OSS) to a simplified Chinese version (SC-OSS) and to validate a new face-scale version of the OSS (FS-OSS), while investigating cross-cultural adaptation, validation, and reproducibility of both versions in patients with shoulder pain. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: The translation and cross-cultural adaptation of the SC-OSS was performed using a forward-backward translation method. The FS-OSS was developed on the basis of the SC-OSS, using the Wong-Baker FACES Pain Rating Scale for reference. Participants were asked to complete the SC-OSS, FS-OSS, Simple Shoulder Test (SST), Constant-Murley score (CMS), and 36-Item Short Form Health Survey (SF-36). Validation and reproducibility were tested by calculating Cronbach α values for internal consistency as well as by intraclass correlation coefficients. Time needed to complete the scores was used to test cross-cultural adaption. RESULTS: A total of 312 respondents participated in the research and completed all outcome measures. The internal consistency was strong, with a Cronbach α of .94 and .91 for the FS-OSS and SC-OSS, respectively. High intraclass correlation coefficient values for the FS-OSS score (0.95) and SC-OSS (0.92) were obtained, which indicated excellent test-retest reliability. The Pearson correlation coefficients of the SC-OSS and FS-OSS with the SST (r = 0.67 and 0.65, respectively), CMS (r = 0.62 and 0.66, respectively), and SF-36 (r = 0.52 and 0.57, respectively) indicated good construct validity. The time needed to complete the FS-OSS was less than that needed for the SC-OSS and SST. CONCLUSION: The FS-OSS and SC-OSS were validated as reliable instruments for patients with shoulder pain. For Chinese patients, the face-scale version was easier to understand than the cross-cultural text version.

Quantitative fit analysis of acromion fracture plating systems using three-dimensional reconstructed scapula fractures - A multi-observer study.

INTRODUCTION: Surgical treatment of displaced acromial and scapula spine fractures may be challenging due to the bony anatomy and variable fracture patterns. This difficulty is accentuated by the limitations of the available scapular plates for fracture fixation. This study compares the quantitative fitting of anatomic scapular plates and clavicle plates, using three-dimensional (3D) printed fractured scapulae. METHODS: Fourteen scapulae with acromion and spine fractures were used for this study. Computerized tomographic (CT) scans of the fractured scapulae were obtained from the Philips picture archiving and communication system (PACS) database of patients admitted to a tertiary teaching hospital in Cape Town, South Africa between 2012 and 2016. The reconstructed scapulae were 3D printed and the anatomical acromion and clavicle plates were templated about the fracture regions. The fit assessment was performed by five observers who classified the plates as no-fit, intermediate fit, and anatomical fit according to the surgical guidelines. RESULTS: The 6-hole anterior clavicle plate performed better than any of the scapular plates as they were able to fit 45.7% of the fractured acromion, including the spine. Among the pre-contoured anatomical scapula plates, both the short and the long acromion plates could fit only 27.3% of the fractured acromion. The intraclass correlation coefficient was 0.965 suggesting excellent consensus among the five observers. CONCLUSION: Clavicle plates were found to be better suited to fit around a scapula fracture in its acromion and spine region.

Assessment and management of shoulder pain at primary care level.

Most patients with shoulder pain will initially visit their community health centre, private general practitioner or family physician, with various levels of experience in the assessment and management of shoulder conditions. Shoulder conditions will range from early, simple ailments that can be treated in the primary care setting, to post-traumatic injuries and complex pathologies requiring the expertise of an orthopaedic surgeon or a fellowship-trained shoulder surgeon. Correct assessment of the patient's shoulder condition at the index consultation is a prerequisite for appropriate management. This article sets out straightforward guidelines to help general practitioners confidently identify the patient's source of shoulder pain and initiate an appropriate management plan at primary care level. Criteria for urgent and elective referral for specialist care are also outlined.

A gender-based comparison of coracoid and glenoid anatomy: CT analysis and discussion of potential impact on the Latarjet procedure.

BACKGROUND: The success of the modified Latarjet procedure depends on proper sizing of the coracoid graft. There is no information available regarding the morphometric relationship between the glenoid cavity and the coracoid process for the South African population. This study aims at measuring the relationship between the glenoid and coracoid morphometries and investigates their gender-related differences. METHODS: Glenohumeral computerized tomography scans of 100 consecutive patients were considered for this study. Morphometric measurements were performed after aligning the coracoid and glenoid in their optimum orientation. These measurements were performed by 2 independent observers. The ratio between glenoid and coracoid measurements was calculated and statistically compared using the Mann-Whitney U test. Intraclass correlation coefficients were calculated to analyze interobserver reliability. All the statistical tests were performed in SPSS v.26, and power calculations in G∗Power v.3.1. RESULTS: An average intraclass correlation coefficient value of 0.79 suggested that the interobserver reliability was good. Except for coracoid length, statistically significant (P < .05) gender differences were observed for all the other morphometries. The coracoid width (16.5 ± 1.4 mm vs. 14.7 ± 1.4 mm) and height (13.6 ± 1.6 mm vs. 10.5 ± 1.5 mm) differed between genders by 1.8 and 3.1 mm, respectively. The glenoid anteroposterior (AP) (25.3 ± 2.9 mm vs. 23.2 ± 2.4 mm) and superioinferior (36.9 ± 1.9 mm vs. 33.7 ± 2.6 mm) measurements differed by 2.1 and 3.3 mm, respectively, between the males and the females. The ratio between the AP width of the glenoid and the coracoid height was also found to be significantly different (P < .05) between the gender groups. These morphometric ratios for the coracoid width (0.66 ± 0.09 mm vs. 0.64 ± 0.08 mm) and the coracoid height (0.55 ± 0.09 mm vs. 0.46 ± 0.07 mm) differed between genders by 0.02 and 0.09, respectively. CONCLUSION: Measurements taken from computerized tomography scans showed significant differences between genders in absolute measurements and in the ratio of the coracoid height to the glenoid AP distance. This could have implications on the ability of the Latarjet procedure to compensate for bone loss in female patients.

An interpopulation comparison of 3-dimensional morphometric measurements of the proximal humerus.

BACKGROUND: Precise anatomic reconstruction of the proximal humerus is essential to a favorable outcome of total shoulder arthroplasty. Because of the wide variation in the geometric features of the proximal humerus, prosthetic designs incorporating these disparities are being developed. METHODS: The aim of this study is to use data obtained from cadavers and computed tomographic scans to investigate the 3-dimensional morphometric parameters of the proximal humerus of South African and Swiss samples and make an interpopulation comparison. In addition, the study combines the interarticular variations between populations with the differences in sex and shoulder sides. With the aid of medical imaging techniques and engineering design tools, various geometric features were measured. RESULTS: The results obtained from these analyses revealed several differences in sex and shoulder sides. On average, the Swiss were larger in most of the measured parameters than the South Africans. The male shoulders of Swiss and South Africans were observed to significantly vary in 4 of the parameters measured. The South African male and female right shoulders varied considerably in one-fourth of the measured shoulder variables. Generally, for both populations, the left and right shoulders of the same individuals were not different in all the measured variables irrespective of sex. CONCLUSION: The knowledge acquired in this study is expected to assist in the development of a population-specific shoulder prosthetic design and surgical planning procedures.

Relationship between the lateral acromion angle and postoperative persistent pain of distal clavicle fracture treated with clavicle hook plate.

BACKGROUND: The clavicular hook plate is an accepted surgical procedure for distal clavicle fractures. The relationship of the characteristics of the hook plate, acromioclavicular joint and acromion morphology, and clinical outcome has remained poorly understood. We reviewed the clinical records of patients who had distal clavicle fractures with different lateral acromion angles treated using a clavicle hook plate and evaluated their clinical outcomes with respect to shoulder pain and acromial morphology. METHODS: We retrospectively reviewed 102 patients with distal clavicle fractures treated with hook plates at our institution from 2010 to 2017. They were divided into four groups according to lateral acromion angle on shoulder AP view X-rays. The angle was defined as the incline angle between the superior surface of distal clavicle and the inferior facet of acromion on coronal plane. We reviewed their clinical features, including Neer's impingement sign, MRI findings, and outcomes using Japanese Orthopaedic Association Scores. The mean follow-up was 25.5 months (range, 24 to 28 months). RESULTS: All patients in group D (large lateral acromion angle (α) > 40°, acromion coronal angle (ß) < 60°) complained of postoperative symptoms. Compared to those with common lateral acromion angle, the incidence of postoperative impingement in group D was undoubtedly much higher (100%). Japanese Orthopaedic Association (JOA) scores in group D were worse at 3 months post-surgery, 3 months post plate removal, and at the last follow-up despite a slightly earlier removal in this group. CONCLUSION: Lateral acromion angle appears to be an important factor in the development of postoperative pain and worse outcomes (JOA scores) in patients treated with the hook plate. The incidence of subacromial impingement and rotator cuff lesion (RCL) increased with the α angle. Early limited mobility and removal of the implant may improve the prognosis and resolve the postoperative shoulder pain. STUDY DESIGN: Retrospective review, level of evidence IV.

Effect of humeral tray placement on impingement-free range of motion and muscle moment arms in reverse shoulder arthroplasty.

BACKGROUND: It has been suggested that onlay humeral tray placement in reverse shoulder arthroplasty can affect impingement and muscle functionality. This study investigates biomechanical changes to the reversed shoulder using a variety of tray positional configurations. METHODS: The reconstructed scapula and humerus from 12 CT scans were used to customise a 3D biomechanical model of the shoulder. Each model underwent virtual RSA surgery using a commercially available prosthesis that was reconstructed from an explant. 17 tray positions were tested: the default location with no offset and 16 offset locations (2.5 and 5 mm radial offsets over 45° circumferential intervals). Impingement and muscle moment arms were measured during three standardised activities, and impingement was measured during an activity of daily living. FINDINGS: Offset direction was found to have an effect (P < 0.05) on extra-articular impingement and muscle moment arms for all activities; whereas, offset distance did not (P > 0.05). Overall, impingement-free range of motion was maximised using a posterolateral tray offset and muscle moment arms were maximised using a medial tray offset. An antagonistic relationship between changes to impingement and muscle moment arms due to tray placement was identified and, consequently, the simultaneous maximisation of both outcome measures was not possible. INTERPRETATION: The functional outcomes of reverse shoulder arthroplasty can be improved by altering onlay humeral tray placement. Due to the antagonistic relationship between the impingement and muscle moment arms, placement of the tray should be guided by patient-specific characteristics.

Treating fractures in upper limb gunshot injuries: The Cape Town experience.

BACKGROUND: Upper extremity gunshot fractures are generally treated conservatively or surgically using open reduction and internal fixation (ORIF), intramedullary nails (IM) or external fixators. However, there is no gold standard for the management of these complex, multi-fragmentary upper extremity fractures. The aim was to describe and identify the injury patterns, management, complications and associated risk factors for upper extremity gunshot fractures. PATIENT AND METHODS: Data of patients with upper extremity gunshot injuries that presented to a Level I Trauma Unit in Cape Town, South Africa was collected prospectively over a ten-month period from June 2014 to April 2015. Clinical notes and radiographs were reviewed retrospectively. RESULTS: Fifty-one of 90 patients (56.7%) with ballistic injuries had fractures, 30% had neurovascular injuries and 75% had additional injuries to other anatomical structures including head, neck, spine, chest, abdomen, pelvis and urogenital tract. Most fractures were diaphyseal, multi-fragmentary and extra-articular. Fractures were treated conservatively in more than half of the cases. Median fracture length was 5.5 centimetres. A longer fracture zone was statistically associated with surgical treatment. When surgically treated, open reduction and internal fixation was most often performed. Median hospital stay was six days. Infection and injury severity prolonged hospital stay. DISCUSSION: In contrast to studies from the USA and Europe, most fractures in this study were managed conservatively. High quality prospective controlled trials are required to evaluate radiographic and clinical outcomes of treatment methods for upper extremity gunshot injuries. LEVEL OF EVIDENCE: IV, case series.