Foot shape and radiographs of free-ranging Nubian giraffe in Uganda

Foot health in zoo giraffe has been a topic of recent research, although little is known about the foot health of free-ranging giraffe. This study describes the foot shape and radiographic pathological changes in 27 young adult Nubian giraffe (Giraffa camelopardalis camelopardalis) from a translocation in Uganda (August 2017). Giraffe feet were observed to have a concave sole, the hoof wall was longest by the toe tip, and the weight-bearing surface of the foot was primarily along the periphery of the foot including hoof wall, parts of the heel, and the edge of the sole. Radiographs showed that pedal osteitis and sesamoid bone cysts were relatively uncommon (3/24 giraffe with osteitis, 1/24 giraffe with sesamoid cysts), and that no giraffe in the study had P3 joint osteoarthritis, P3 rotation, or P3 fractures. Radiographs consistently demonstrated a positive palmar/plantar angle with the sole of the hoof thicker at the heel than by the toe tip, with the non weight-bearing palmar/plantar angle measuring 1.6°- 4.3°. This is the first systematic review of foot shape and radiographs in free-ranging giraffe and demonstrates a low prevalence of foot pathologies. This study suggests qualitative differences in foot shape, foot health, radiographic anatomy, and foot pathologies when comparing free-ranging and zoo giraffe. Further research is needed to identify why these differences occur and whether husbandry modifications could help improve zoo giraffe foot health and prevent associated lameness.

Prevalence of metacarpophalangeal sesamoid bones of the hand in Turkish population

Objectives: This study aims to investigate the prevalence and location of the metacarpophalangeal (MCP) sesamoid bones using computed tomography (CT) images. Patients and methods: A total of 767 hands of 735 patients (503 males, 232 females; mean age: 36.9±17.0 years; range, 18 to 105 years) obtained from picture archiving and communication system were retrospectively analyzed between January 2016 and December 2019. The sesamoid bones of MCP joints I, II, III, IV, and V were recorded. Data including age, sex, side, number, pathologies, and location of the sesamoid bones were recorded. Results: The prevalence of sesamoid bones was found to be 100%, 37.61%, 1.17%, 0.5%, and 80% in MCP I, II, III, IV, and V, respectively. There was no significant correlation between the sex of the patient and presence of sesamoid bone at MCP II or MCP V (p>0.970 and p=0.176, respectively). The presence of sesamoid bone at MCP II was statistically significantly correlated with the presence of sesamoid bone at MCP V (p<0.001). There was no statistically significant difference in the side and sesamoid prevalence in the remaining 703 patients (p>0.05). Conclusion: The prevalence of MCP V sesamoid bone is higher than previous studies from our country. The CT of hand can be used to determine sesamoid fractures and degenerative conditions of sesamoids.

Sudden death caused by spinal cord injury associated with vertebral fractures and fetlock failure in a Thoroughbred racehorse

The most prevalent causes of death in racehorses are musculoskeletal injuries, causing ~83% of deaths within the racing industry in California and elsewhere. The vast majority of these injuries have preexisting lesions that predispose to fatal injury. A 4-y-old Thoroughbred colt suffered an acute suspensory apparatus failure, including biaxial proximal sesamoid bone fractures of the right front fetlock, causing loss of support of the fetlock joint and consequent fall with fractures of the cervical and sacral spine. Cervical fracture caused spinal cord damage that resulted in sudden death. A preexisting lesion in the medial proximal sesamoid bone likely predisposed to complete fracture of this bone and fetlock breakdown. Interestingly, a comparable osteopenic lesion was present in the intact medial proximal sesamoid bone of the left forelimb, which is consistent with bilateral repetitive overuse injury in racehorses. The morphologic features of the cervical and sacral spine fractures were compatible with acute injury; no evidence of preexisting lesions was seen. Most likely, these acute vertebral fractures occurred as a result of the horse falling. This case emphasizes the importance of performing a detailed autopsy in horses that suffer an appendicular musculoskeletal injury, particularly in fatal cases when the horse dies following a leg injury.

Fabellar prevalence, parameters and association with medial meniscal tear: causality or coincidence?

Background: Fabella is a sesamoid bone of knee that has potential biomechanical function. The correlation between medial meniscal (MM) tear and fabella has not been rigorously examined. The aim of this study is to examine the fabellar prevalence and parameters in Chinese population and test the hypothesis that fabellar presence and morphology are associated with MM tear.Methods: A total of 1011 knee magnetic resonance imaging scans were analyzed. The fabellar presence was documented and parameters were measured. Further ratios were calculated to present fabellar morphology. Differences among subgroups were compared and correlation of fabellar presence and parameters with advancing age was assessed by Spearman correlation analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to investigate whether factors have relationship with MM tear. Diagnostic performance of risk factors was assessed and cut values were determined.Results: The overall prevalence of fabellae was 39.8% and increased with the increasing age (r = .237, P < .001). The fabellar were larger in male and ones with an articulating groove (all p < .001). The length/thickness ratio and width/thickness ratio were found significantly different between gender, age and articulating groove condition (all P < .05) and showed a moderate correlation with age (r = .463, p < .001; r = .303, p < .001), respectively. Fabella presented more often in knees with MM tears with a multivariate OR of 2.960 (95% CI, 1.853-3.903). Age, fabellar length, width, length/thickness ratio and width/thickness ratio yielded an area under the ROC curve (AUC) of 0.604-0.766 to predict an MM tear. In combination with age, fabellar width and length/thickness ratio, the diagnostic performance was improved to an AUC of 0.791 (95% CI, 0.744-0.837), a sensitivity of 73.0% and a specificity of 74.6% (OR, 7.939; 95% CI, 4.094-12.852). Conclusion: The presence of fabellae, increased fabellar length and width as well as flatter fabellar morphology, are significantly associated with an increased risk for MM tear. These findings might aid clinicians in identifying patients at risk for a MM tear and informing them.

Correlative Study Between the Sesamoid Bones under the Head of the First Metatarsal and the Development of Hallux Valgus Determined with Radiographs

Objective. To study the correlative between the sesamoid bones under the head of the first metatarsal and the development of hallux valgus determined with radiographs.Methods.The measurements were performed on the X-ray of 300 normal feet and 300 cases of hallux valgus. The following parameters were measured: hallux valgus angle(HVA); the first-second intermetatarsal angle(IMA) between the axes of the first and second metatarsal;the length of the second metatarsal（CD）;the position of tibial sesamoid(TSP ) measured the percent formed between the tibial sesamoid and the centreline of the first metatarsal;the position of fibular sesamoid(FSP) measured tangent value between fibular sesamoid bone and lateral cortex of first metatarsal bone ; the absolute distances (AB) from the centre of the tibial sesamoid to the long axis of the second metatarsal, the absolute distances (EF) from the centre of the fibular sesamoid to the long axis of the second metatarsal and the absolute distance (GH) from the centre of the tibial sesamoid to the centre of the fibular sesamoid. Then calculate the ratio of AB to CD (K1), EF to CD (K2) and GH to CD (K3). Results.HVA moderately positively correlates with TSP and moderately negatively correlates with FSP in subjects with HVA ≥ 20°. HVA and FSP are strongly negatively correlated in the hallux valgus group. Conclusion.The dislocation of sesamoid bone under the first metatarsal head is an important pathological factor leading to valgus. HVA is positively correlated with TSP and negatively correlated with FSP.

Dislocation of the metacarpophalangeal joint of the index finger requiring open reduction due to the presence of an intra-articular sesamoid bone

Complex dislocation of the metacarpophalangeal joint of the index finger is rare and often requires surgical intervention. Here, we present a case of an index finger metacarpophalangeal joint dislocation requiring open reduction due to obstruction by a displaced volar plate and the intra-articular entrapment of a sesamoid bone. Surgical approach was performed dorsally, allowing easy visualization of the volar plate and sesamoid bone as well as minimizing risk to the radial digital nerve to the index finger. Postoperatively, the patient reported good functional return despite the delay in definitive management.

A modified minimally invasive osteotomy for hallux valgus enables reduction of malpositioned sesamoid bones

Background: Current minimally invasive distal metatarsal osteotomy for hallux valgus (HV) is V-shaped, which prevents correcting the rotational metatarsal head deformity and reduction of sesamoid bones. We aimed to determine the optimal method for sesamoid bone reduction in HV surgery.Methods: We reviewed the records of 53 patients who underwent HV surgery by a single surgeon from 2017 to 2019 according to one of three techniques: open chevron osteotomy (n=19), minimally invasive V-shaped osteotomy (n=18) and a modified, straight minimally invasive osteotomy (n=16). Sesamoid position was graded using the Hardy and Clapham method based on standing radiographs. Results: Postoperative sesamoid position scores were significantly lower (better) following the modified osteotomy than following open chevron osteotomy and V-shaped osteotomy (1.44±0.81, 3.74±1.48 and 4.61±1.09, respectively, P<0.001); and the mean change in score was greater (P<0.001). Conclusion: Modified minimally invasive osteotomy was superior to the two other techniques, in the correction of HV deformity in all planes, including sesamoid reduction.